Merge pull request #17 from Luro02/master

Lots of changes

Cargo.toml

@@ -9,13 +9,18 @@ readme = "README.md"
 license = "MIT OR Apache-2.0"
 keywords = ["hls", "m3u8"]
 edition = "2018"
+categories = ["parser"]
 
 [badges]
 travis-ci = {repository = "sile/hls_m3u8"}
 codecov = {repository = "sile/hls_m3u8"}
 
 [dependencies]
-trackable = "0.2"
+getset = "0.0.8"
+failure = "0.1.5"
+derive_builder = "0.7.2"
+url = "2.1.0"
+chrono = "0.4.9"
 
 [dev-dependencies]
-clap = "2"
+clap = "2"

examples/parse.rs

@@ -1,12 +1,9 @@
 extern crate clap;
 extern crate hls_m3u8;
-#[macro_use]
-extern crate trackable;
 
 use clap::{App, Arg};
 use hls_m3u8::{MasterPlaylist, MediaPlaylist};
 use std::io::{self, Read};
-use trackable::error::Failure;
 
 fn main() {
     let matches = App::new("parse")
@@ -19,17 +16,15 @@ fn main() {
         )
         .get_matches();
     let mut m3u8 = String::new();
-    track_try_unwrap!(io::stdin()
-        .read_to_string(&mut m3u8)
-        .map_err(Failure::from_error));
+    io::stdin().read_to_string(&mut m3u8).unwrap();
 
     match matches.value_of("M3U8_TYPE").unwrap() {
         "media" => {
-            let playlist: MediaPlaylist = track_try_unwrap!(m3u8.parse());
+            let playlist: MediaPlaylist = m3u8.parse().unwrap();
             println!("{}", playlist);
         }
         "master" => {
-            let playlist: MasterPlaylist = track_try_unwrap!(m3u8.parse());
+            let playlist: MasterPlaylist = m3u8.parse().unwrap();
             println!("{}", playlist);
         }
         _ => unreachable!(),

src/attribute.rs

@@ -1,103 +1,138 @@
-use crate::{ErrorKind, Result};
-use std::collections::HashSet;
-use std::str;
+use std::collections::HashMap;
+use std::ops::{Deref, DerefMut};
+use std::str::FromStr;
 
-#[derive(Debug)]
-pub struct AttributePairs<'a> {
-    input: &'a str,
-    visited_keys: HashSet<&'a str>,
-}
-impl<'a> AttributePairs<'a> {
-    pub fn parse(input: &'a str) -> Self {
-        AttributePairs {
-            input,
-            visited_keys: HashSet::new(),
-        }
-    }
+use crate::Error;
 
-    fn parse_name(&mut self) -> Result<&'a str> {
-        for i in 0..self.input.len() {
-            match self.input.as_bytes()[i] {
-                b'=' => {
-                    let (key, _) = self.input.split_at(i);
-                    let (_, rest) = self.input.split_at(i + 1);
-                    self.input = rest;
-                    return Ok(key);
-                }
-                b'A'..=b'Z' | b'0'..=b'9' | b'-' => {}
-                _ => track_panic!(
-                    ErrorKind::InvalidInput,
-                    "Malformed attribute name: {:?}",
-                    self.input
-                ),
-            }
-        }
-        track_panic!(
-            ErrorKind::InvalidInput,
-            "No attribute value: {:?}",
-            self.input
-        );
-    }
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct AttributePairs(HashMap<String, String>);
 
-    fn parse_raw_value(&mut self) -> &'a str {
-        let mut in_quote = false;
-        let mut value_end = self.input.len();
-        let mut next = self.input.len();
-        for (i, c) in self.input.bytes().enumerate() {
-            match c {
-                b'"' => {
-                    in_quote = !in_quote;
-                }
-                b',' if !in_quote => {
-                    value_end = i;
-                    next = i + 1;
-                    break;
-                }
-                _ => {}
-            }
-        }
-        let (value, _) = self.input.split_at(value_end);
-        let (_, rest) = self.input.split_at(next);
-        self.input = rest;
-        value
+impl AttributePairs {
+    pub fn new() -> Self {
+        Self::default()
     }
 }
-impl<'a> Iterator for AttributePairs<'a> {
-    type Item = Result<(&'a str, &'a str)>;
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.input.is_empty() {
-            return None;
+
+impl Deref for AttributePairs {
+    type Target = HashMap<String, String>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for AttributePairs {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl IntoIterator for AttributePairs {
+    type Item = (String, String);
+    type IntoIter = ::std::collections::hash_map::IntoIter<String, String>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a AttributePairs {
+    type Item = (&'a String, &'a String);
+    type IntoIter = ::std::collections::hash_map::Iter<'a, String, String>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.iter()
+    }
+}
+
+impl FromStr for AttributePairs {
+    type Err = Error;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let mut result = AttributePairs::new();
+
+        for line in split(input, ',') {
+            let pair = split(line.trim(), '=');
+
+            if pair.len() < 2 {
+                return Err(Error::invalid_input());
+            }
+
+            let key = pair[0].to_uppercase();
+            let value = pair[1].to_string();
+
+            result.insert(key.to_string(), value.to_string());
         }
 
-        let result = || -> Result<(&'a str, &'a str)> {
-            let key = track!(self.parse_name())?;
-            track_assert!(
-                self.visited_keys.insert(key),
-                ErrorKind::InvalidInput,
-                "Duplicate attribute key: {:?}",
-                key
-            );
-
-            let value = self.parse_raw_value();
-            Ok((key, value))
-        }();
-        Some(result)
+        dbg!(&result);
+        Ok(result)
     }
 }
 
+fn split(value: &str, terminator: char) -> Vec<String> {
+    let mut result = vec![];
+
+    let mut inside_quotes = false;
+    let mut temp_string = String::new();
+
+    for c in value.chars() {
+        match c {
+            '"' => {
+                if inside_quotes {
+                    inside_quotes = false;
+                } else {
+                    inside_quotes = true;
+                }
+                temp_string.push(c);
+            }
+            k if (k == terminator) => {
+                if !inside_quotes {
+                    result.push(temp_string);
+                    temp_string = String::new();
+                } else {
+                    temp_string.push(c);
+                }
+            }
+            _ => {
+                temp_string.push(c);
+            }
+        }
+    }
+    result.push(temp_string);
+
+    result
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
 
     #[test]
-    fn it_works() {
-        let mut pairs = AttributePairs::parse("FOO=BAR,BAR=\"baz,qux\",ABC=12.3");
-        assert_eq!(pairs.next().map(|x| x.ok()), Some(Some(("FOO", "BAR"))));
-        assert_eq!(
-            pairs.next().map(|x| x.ok()),
-            Some(Some(("BAR", "\"baz,qux\"")))
-        );
-        assert_eq!(pairs.next().map(|x| x.ok()), Some(Some(("ABC", "12.3"))));
-        assert_eq!(pairs.next().map(|x| x.ok()), None)
+    fn test_parser() {
+        let pairs = ("FOO=BAR,BAR=\"baz,qux\",ABC=12.3")
+            .parse::<AttributePairs>()
+            .unwrap();
+
+        let mut iterator = pairs.iter();
+        assert!(iterator.any(|(k, v)| k == "FOO" && "BAR" == v));
+
+        let mut iterator = pairs.iter();
+        assert!(iterator.any(|(k, v)| k == "BAR" && v == "\"baz,qux\""));
+
+        let mut iterator = pairs.iter();
+        assert!(iterator.any(|(k, v)| k == "ABC" && v == "12.3"));
+    }
+
+    #[test]
+    fn test_iterator() {
+        let mut attrs = AttributePairs::new();
+        attrs.insert("key_01".to_string(), "value_01".to_string());
+        attrs.insert("key_02".to_string(), "value_02".to_string());
+
+        let mut iterator = attrs.iter();
+        assert!(iterator.any(|(k, v)| k == "key_01" && v == "value_01"));
+
+        let mut iterator = attrs.iter();
+        assert!(iterator.any(|(k, v)| k == "key_02" && v == "value_02"));
     }
 }

src/error.rs

@@ -1,13 +1,224 @@
-use trackable::error::{ErrorKind as TrackableErrorKind, TrackableError};
+use std::error;
+use std::fmt;
 
-/// This crate specific `Error` type.
-#[derive(Debug, Clone, TrackableError)]
-pub struct Error(TrackableError<ErrorKind>);
+use failure::{Backtrace, Context, Fail};
 
-/// Possible error kinds.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-#[allow(missing_docs)]
+/// This crate specific `Result` type.
+pub type Result<T> = std::result::Result<T, Error>;
+
+/// The ErrorKind.
+#[derive(Debug, Fail, Clone, PartialEq, Eq)]
 pub enum ErrorKind {
+    #[fail(display = "ChronoParseError: {}", _0)]
+    /// An error from the [Chrono](chrono) crate.
+    ChronoParseError(String),
+    #[fail(display = "UrlParseError: {}", _0)]
+    /// An error from the [Url](url) crate.
+    UrlParseError(String),
+    #[fail(display = "UnknownError: {}", _0)]
+    /// An unknown error occured.
+    UnknownError(String),
+
+    #[fail(display = "A value is missing for the attribute {}", _0)]
+    /// A required value is missing.
+    MissingValue(String),
+
+    #[fail(display = "Invalid Input")]
+    /// Error for anything.
     InvalidInput,
+
+    #[fail(display = "ParseIntError: {}", _0)]
+    /// Failed to parse a String to int.
+    ParseIntError(String),
+
+    #[fail(display = "ParseFloatError: {}", _0)]
+    /// Failed to parse a String to float.
+    ParseFloatError(String),
+
+    #[fail(display = "MissingTag: Expected {} at the start of {:?}", tag, input)]
+    /// A tag is missing, that is required at the start of the input.
+    MissingTag {
+        /// The required tag.
+        tag: String,
+        /// The unparsed input data.
+        input: String,
+    },
+
+    #[fail(display = "CustomError: {}", _0)]
+    /// A custom error.
+    Custom(String),
+
+    #[fail(display = "Unmatched Group: {:?}", _0)]
+    /// Unmatched Group
+    UnmatchedGroup(String),
+
+    #[fail(display = "Unknown Protocol version: {:?}", _0)]
+    /// Unknown m3u8 version. This library supports up to ProtocolVersion 7.
+    UnknownProtocolVersion(String),
+
+    #[fail(display = "IoError: {}", _0)]
+    /// Some io error
+    Io(String),
+
+    #[fail(
+        display = "VersionError: required_version: {:?}, specified_version: {:?}",
+        _0, _1
+    )]
+    /// This error occurs, if there is a ProtocolVersion mismatch.
+    VersionError(String, String),
+
+    #[fail(display = "BuilderError: {}", _0)]
+    /// An Error from a Builder.
+    BuilderError(String),
+
+    /// Hints that destructuring should not be exhaustive.
+    ///
+    /// This enum may grow additional variants, so this makes sure clients
+    /// don't count on exhaustive matching. (Otherwise, adding a new variant
+    /// could break existing code.)
+    #[doc(hidden)]
+    #[fail(display = "Invalid error")]
+    __Nonexhaustive,
+}
+
+#[derive(Debug)]
+/// The Error type of this library.
+pub struct Error {
+    inner: Context<ErrorKind>,
+}
+
+impl Fail for Error {
+    fn cause(&self) -> Option<&dyn Fail> {
+        self.inner.cause()
+    }
+
+    fn backtrace(&self) -> Option<&Backtrace> {
+        self.inner.backtrace()
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.inner.fmt(f)
+    }
+}
+
+impl From<ErrorKind> for Error {
+    fn from(kind: ErrorKind) -> Error {
+        Error::from(Context::new(kind))
+    }
+}
+
+impl From<Context<ErrorKind>> for Error {
+    fn from(inner: Context<ErrorKind>) -> Error {
+        Error { inner }
+    }
+}
+
+impl Error {
+    pub(crate) fn unknown<T>(value: T) -> Self
+    where
+        T: error::Error,
+    {
+        Self::from(ErrorKind::UnknownError(value.to_string()))
+    }
+
+    pub(crate) fn missing_value<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::MissingValue(value.to_string()))
+    }
+
+    pub(crate) fn invalid_input() -> Self {
+        Self::from(ErrorKind::InvalidInput)
+    }
+
+    pub(crate) fn parse_int_error<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::ParseIntError(value.to_string()))
+    }
+
+    pub(crate) fn parse_float_error<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::ParseFloatError(value.to_string()))
+    }
+
+    pub(crate) fn missing_tag<T, U>(tag: T, input: U) -> Self
+    where
+        T: ToString,
+        U: ToString,
+    {
+        Self::from(ErrorKind::MissingTag {
+            tag: tag.to_string(),
+            input: input.to_string(),
+        })
+    }
+
+    pub(crate) fn unmatched_group<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::UnmatchedGroup(value.to_string()))
+    }
+
+    pub(crate) fn custom<T>(value: T) -> Self
+    where
+        T: fmt::Display,
+    {
+        Self::from(ErrorKind::Custom(value.to_string()))
+    }
+
+    pub(crate) fn unknown_protocol_version<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::UnknownProtocolVersion(value.to_string()))
+    }
+
+    pub(crate) fn io<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::Io(value.to_string()))
+    }
+
+    pub(crate) fn required_version<T, U>(required_version: T, specified_version: U) -> Self
+    where
+        T: ToString,
+        U: ToString,
+    {
+        Self::from(ErrorKind::VersionError(
+            required_version.to_string(),
+            specified_version.to_string(),
+        ))
+    }
+
+    pub(crate) fn builder_error<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::BuilderError(value.to_string()))
+    }
+
+    pub(crate) fn url<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::UrlParseError(value.to_string()))
+    }
+
+    pub(crate) fn chrono<T: ToString>(value: T) -> Self {
+        Self::from(ErrorKind::ChronoParseError(value.to_string()))
+    }
+}
+
+impl From<::std::num::ParseIntError> for Error {
+    fn from(value: ::std::num::ParseIntError) -> Self {
+        Error::parse_int_error(value)
+    }
+}
+
+impl From<::std::num::ParseFloatError> for Error {
+    fn from(value: ::std::num::ParseFloatError) -> Self {
+        Error::parse_float_error(value)
+    }
+}
+
+impl From<::std::io::Error> for Error {
+    fn from(value: ::std::io::Error) -> Self {
+        Error::io(value)
+    }
+}
+
+impl From<::url::ParseError> for Error {
+    fn from(value: ::url::ParseError) -> Self {
+        Error::url(value)
+    }
+}
+
+impl From<::chrono::ParseError> for Error {
+    fn from(value: ::chrono::ParseError) -> Self {
+        Error::chrono(value)
+    }
 }
-impl TrackableErrorKind for ErrorKind {}

src/lib.rs

@@ -1,3 +1,9 @@
+#![warn(
+    //clippy::pedantic,
+    clippy::nursery,
+    clippy::cargo
+)]
+#![warn(missing_docs)]
 //! [HLS] m3u8 parser/generator.
 //!
 //! [HLS]: https://tools.ietf.org/html/rfc8216
@@ -20,13 +26,10 @@
 //!
 //! assert!(m3u8.parse::<MediaPlaylist>().is_ok());
 //! ```
-#![warn(missing_docs)]
-#[macro_use]
-extern crate trackable;
 
 pub use error::{Error, ErrorKind};
 pub use master_playlist::{MasterPlaylist, MasterPlaylistBuilder};
-pub use media_playlist::{MediaPlaylist, MediaPlaylistBuilder, MediaPlaylistOptions};
+pub use media_playlist::{MediaPlaylist, MediaPlaylistBuilder};
 pub use media_segment::{MediaSegment, MediaSegmentBuilder};
 
 pub mod tags;
@@ -40,5 +43,4 @@ mod media_playlist;
 mod media_segment;
 mod utils;
 
-/// This crate specific `Result` type.
-pub type Result<T> = std::result::Result<T, Error>;
+pub use error::Result;

src/line.rs

@@ -1,81 +1,99 @@
-use crate::tags;
-use crate::types::SingleLineString;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
+use std::ops::{Deref, DerefMut};
 use std::str::FromStr;
 
-#[derive(Debug)]
-pub struct Lines<'a> {
-    input: &'a str,
-}
-impl<'a> Lines<'a> {
-    pub fn new(input: &'a str) -> Self {
-        Lines { input }
-    }
+use url::Url;
 
-    fn read_line(&mut self) -> Result<Line<'a>> {
-        let mut end = self.input.len();
-        let mut next_start = self.input.len();
-        let mut adjust = 0;
-        let mut next_line_of_ext_x_stream_inf = false;
-        for (i, c) in self.input.char_indices() {
-            match c {
-                '\n' => {
-                    if !next_line_of_ext_x_stream_inf
-                        && self.input.starts_with(tags::ExtXStreamInf::PREFIX)
-                    {
-                        next_line_of_ext_x_stream_inf = true;
-                        adjust = 0;
-                        continue;
-                    }
-                    next_start = i + 1;
-                    end = i - adjust;
-                    break;
-                }
-                '\r' => {
-                    adjust = 1;
-                }
-                _ => {
-                    track_assert!(!c.is_control(), ErrorKind::InvalidInput);
-                    adjust = 0;
-                }
+use crate::tags;
+use crate::Error;
+
+#[derive(Debug, Default)]
+pub struct Lines(Vec<Line>);
+
+impl Lines {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+impl FromStr for Lines {
+    type Err = Error;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let mut result = Lines::new();
+
+        let mut stream_inf = false;
+        let mut stream_inf_line = None;
+
+        for l in input.lines() {
+            let line = l.trim();
+
+            // ignore empty lines
+            if line.len() == 0 {
+                continue;
             }
+
+            let pline = {
+                if line.starts_with(tags::ExtXStreamInf::PREFIX) {
+                    stream_inf = true;
+                    stream_inf_line = Some(line);
+
+                    continue;
+                } else if line.starts_with("#EXT") {
+                    Line::Tag(line.parse()?)
+                } else if line.starts_with("#") {
+                    continue; // ignore comments
+                } else {
+                    // stream inf line needs special treatment
+                    if stream_inf {
+                        stream_inf = false;
+                        if let Some(first_line) = stream_inf_line {
+                            let res = Line::Tag(format!("{}\n{}", first_line, line).parse()?);
+                            stream_inf_line = None;
+                            res
+                        } else {
+                            continue;
+                        }
+                    } else {
+                        Line::Uri(line.trim().parse()?)
+                    }
+                }
+            };
+
+            result.push(pline);
         }
-        let raw_line = &self.input[..end];
-        let line = if raw_line.is_empty() {
-            Line::Blank
-        } else if raw_line.starts_with("#EXT") {
-            Line::Tag(track!(raw_line.parse())?)
-        } else if raw_line.starts_with('#') {
-            Line::Comment(raw_line)
-        } else {
-            let uri = track!(SingleLineString::new(raw_line))?;
-            Line::Uri(uri)
-        };
-        self.input = &self.input[next_start..];
-        Ok(line)
-    }
-}
-impl<'a> Iterator for Lines<'a> {
-    type Item = Result<Line<'a>>;
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.input.is_empty() {
-            return None;
-        }
-        match track!(self.read_line()) {
-            Err(e) => Some(Err(e)),
-            Ok(line) => Some(Ok(line)),
-        }
+
+        Ok(result)
+    }
+}
+
+impl IntoIterator for Lines {
+    type Item = Line;
+    type IntoIter = ::std::vec::IntoIter<Line>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
+    }
+}
+
+impl Deref for Lines {
+    type Target = Vec<Line>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Lines {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
     }
 }
 
-#[allow(clippy::large_enum_variant)]
 #[derive(Debug, PartialEq, Eq)]
-pub enum Line<'a> {
-    Blank,
-    Comment(&'a str),
+pub enum Line {
     Tag(Tag),
-    Uri(SingleLineString),
+    Uri(Url),
 }
 
 #[allow(clippy::large_enum_variant)]
@@ -103,86 +121,89 @@ pub enum Tag {
     ExtXSessionKey(tags::ExtXSessionKey),
     ExtXIndependentSegments(tags::ExtXIndependentSegments),
     ExtXStart(tags::ExtXStart),
-    Unknown(SingleLineString),
+    Unknown(String),
 }
+
 impl fmt::Display for Tag {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            Tag::ExtM3u(ref t) => t.fmt(f),
-            Tag::ExtXVersion(ref t) => t.fmt(f),
-            Tag::ExtInf(ref t) => t.fmt(f),
-            Tag::ExtXByteRange(ref t) => t.fmt(f),
-            Tag::ExtXDiscontinuity(ref t) => t.fmt(f),
-            Tag::ExtXKey(ref t) => t.fmt(f),
-            Tag::ExtXMap(ref t) => t.fmt(f),
-            Tag::ExtXProgramDateTime(ref t) => t.fmt(f),
-            Tag::ExtXDateRange(ref t) => t.fmt(f),
-            Tag::ExtXTargetDuration(ref t) => t.fmt(f),
-            Tag::ExtXMediaSequence(ref t) => t.fmt(f),
-            Tag::ExtXDiscontinuitySequence(ref t) => t.fmt(f),
-            Tag::ExtXEndList(ref t) => t.fmt(f),
-            Tag::ExtXPlaylistType(ref t) => t.fmt(f),
-            Tag::ExtXIFramesOnly(ref t) => t.fmt(f),
-            Tag::ExtXMedia(ref t) => t.fmt(f),
-            Tag::ExtXStreamInf(ref t) => t.fmt(f),
-            Tag::ExtXIFrameStreamInf(ref t) => t.fmt(f),
-            Tag::ExtXSessionData(ref t) => t.fmt(f),
-            Tag::ExtXSessionKey(ref t) => t.fmt(f),
-            Tag::ExtXIndependentSegments(ref t) => t.fmt(f),
-            Tag::ExtXStart(ref t) => t.fmt(f),
-            Tag::Unknown(ref t) => t.fmt(f),
+        match &self {
+            Tag::ExtM3u(value) => value.fmt(f),
+            Tag::ExtXVersion(value) => value.fmt(f),
+            Tag::ExtInf(value) => value.fmt(f),
+            Tag::ExtXByteRange(value) => value.fmt(f),
+            Tag::ExtXDiscontinuity(value) => value.fmt(f),
+            Tag::ExtXKey(value) => value.fmt(f),
+            Tag::ExtXMap(value) => value.fmt(f),
+            Tag::ExtXProgramDateTime(value) => value.fmt(f),
+            Tag::ExtXDateRange(value) => value.fmt(f),
+            Tag::ExtXTargetDuration(value) => value.fmt(f),
+            Tag::ExtXMediaSequence(value) => value.fmt(f),
+            Tag::ExtXDiscontinuitySequence(value) => value.fmt(f),
+            Tag::ExtXEndList(value) => value.fmt(f),
+            Tag::ExtXPlaylistType(value) => value.fmt(f),
+            Tag::ExtXIFramesOnly(value) => value.fmt(f),
+            Tag::ExtXMedia(value) => value.fmt(f),
+            Tag::ExtXStreamInf(value) => value.fmt(f),
+            Tag::ExtXIFrameStreamInf(value) => value.fmt(f),
+            Tag::ExtXSessionData(value) => value.fmt(f),
+            Tag::ExtXSessionKey(value) => value.fmt(f),
+            Tag::ExtXIndependentSegments(value) => value.fmt(f),
+            Tag::ExtXStart(value) => value.fmt(f),
+            Tag::Unknown(value) => value.fmt(f),
         }
     }
 }
+
 impl FromStr for Tag {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
         if s.starts_with(tags::ExtM3u::PREFIX) {
-            track!(s.parse().map(Tag::ExtM3u))
+            s.parse().map(Tag::ExtM3u)
         } else if s.starts_with(tags::ExtXVersion::PREFIX) {
-            track!(s.parse().map(Tag::ExtXVersion))
+            s.parse().map(Tag::ExtXVersion)
         } else if s.starts_with(tags::ExtInf::PREFIX) {
-            track!(s.parse().map(Tag::ExtInf))
+            s.parse().map(Tag::ExtInf)
         } else if s.starts_with(tags::ExtXByteRange::PREFIX) {
-            track!(s.parse().map(Tag::ExtXByteRange))
+            s.parse().map(Tag::ExtXByteRange)
         } else if s.starts_with(tags::ExtXDiscontinuity::PREFIX) {
-            track!(s.parse().map(Tag::ExtXDiscontinuity))
+            s.parse().map(Tag::ExtXDiscontinuity)
         } else if s.starts_with(tags::ExtXKey::PREFIX) {
-            track!(s.parse().map(Tag::ExtXKey))
+            s.parse().map(Tag::ExtXKey)
         } else if s.starts_with(tags::ExtXMap::PREFIX) {
-            track!(s.parse().map(Tag::ExtXMap))
+            s.parse().map(Tag::ExtXMap)
         } else if s.starts_with(tags::ExtXProgramDateTime::PREFIX) {
-            track!(s.parse().map(Tag::ExtXProgramDateTime))
+            s.parse().map(Tag::ExtXProgramDateTime)
         } else if s.starts_with(tags::ExtXTargetDuration::PREFIX) {
-            track!(s.parse().map(Tag::ExtXTargetDuration))
+            s.parse().map(Tag::ExtXTargetDuration)
         } else if s.starts_with(tags::ExtXDateRange::PREFIX) {
-            track!(s.parse().map(Tag::ExtXDateRange))
+            s.parse().map(Tag::ExtXDateRange)
         } else if s.starts_with(tags::ExtXMediaSequence::PREFIX) {
-            track!(s.parse().map(Tag::ExtXMediaSequence))
+            s.parse().map(Tag::ExtXMediaSequence)
         } else if s.starts_with(tags::ExtXDiscontinuitySequence::PREFIX) {
-            track!(s.parse().map(Tag::ExtXDiscontinuitySequence))
+            s.parse().map(Tag::ExtXDiscontinuitySequence)
         } else if s.starts_with(tags::ExtXEndList::PREFIX) {
-            track!(s.parse().map(Tag::ExtXEndList))
+            s.parse().map(Tag::ExtXEndList)
         } else if s.starts_with(tags::ExtXPlaylistType::PREFIX) {
-            track!(s.parse().map(Tag::ExtXPlaylistType))
+            s.parse().map(Tag::ExtXPlaylistType)
         } else if s.starts_with(tags::ExtXIFramesOnly::PREFIX) {
-            track!(s.parse().map(Tag::ExtXIFramesOnly))
+            s.parse().map(Tag::ExtXIFramesOnly)
         } else if s.starts_with(tags::ExtXMedia::PREFIX) {
-            track!(s.parse().map(Tag::ExtXMedia))
+            s.parse().map(Tag::ExtXMedia)
         } else if s.starts_with(tags::ExtXStreamInf::PREFIX) {
-            track!(s.parse().map(Tag::ExtXStreamInf))
+            s.parse().map(Tag::ExtXStreamInf)
         } else if s.starts_with(tags::ExtXIFrameStreamInf::PREFIX) {
-            track!(s.parse().map(Tag::ExtXIFrameStreamInf))
+            s.parse().map(Tag::ExtXIFrameStreamInf)
         } else if s.starts_with(tags::ExtXSessionData::PREFIX) {
-            track!(s.parse().map(Tag::ExtXSessionData))
+            s.parse().map(Tag::ExtXSessionData)
         } else if s.starts_with(tags::ExtXSessionKey::PREFIX) {
-            track!(s.parse().map(Tag::ExtXSessionKey))
+            s.parse().map(Tag::ExtXSessionKey)
         } else if s.starts_with(tags::ExtXIndependentSegments::PREFIX) {
-            track!(s.parse().map(Tag::ExtXIndependentSegments))
+            s.parse().map(Tag::ExtXIndependentSegments)
         } else if s.starts_with(tags::ExtXStart::PREFIX) {
-            track!(s.parse().map(Tag::ExtXStart))
+            s.parse().map(Tag::ExtXStart)
         } else {
-            track!(SingleLineString::new(s)).map(Tag::Unknown)
+            Ok(Tag::Unknown(s.to_string()))
         }
     }
 }

src/master_playlist.rs

@@ -1,251 +1,68 @@
-use crate::line::{Line, Lines, Tag};
-use crate::tags::{
-    ExtM3u, ExtXIFrameStreamInf, ExtXIndependentSegments, ExtXMedia, ExtXSessionData,
-    ExtXSessionKey, ExtXStart, ExtXStreamInf, ExtXVersion, MasterPlaylistTag,
-};
-use crate::types::{ClosedCaptions, MediaType, ProtocolVersion, QuotedString};
-use crate::{Error, ErrorKind, Result};
 use std::collections::HashSet;
 use std::fmt;
 use std::iter;
 use std::str::FromStr;
 
-/// Master playlist builder.
-#[derive(Debug, Clone)]
-pub struct MasterPlaylistBuilder {
-    version: Option<ProtocolVersion>,
-    independent_segments_tag: Option<ExtXIndependentSegments>,
-    start_tag: Option<ExtXStart>,
-    media_tags: Vec<ExtXMedia>,
-    stream_inf_tags: Vec<ExtXStreamInf>,
-    i_frame_stream_inf_tags: Vec<ExtXIFrameStreamInf>,
-    session_data_tags: Vec<ExtXSessionData>,
-    session_key_tags: Vec<ExtXSessionKey>,
-}
-impl MasterPlaylistBuilder {
-    /// Makes a new `MasterPlaylistBuilder` instance.
-    pub fn new() -> Self {
-        MasterPlaylistBuilder {
-            version: None,
-            independent_segments_tag: None,
-            start_tag: None,
-            media_tags: Vec::new(),
-            stream_inf_tags: Vec::new(),
-            i_frame_stream_inf_tags: Vec::new(),
-            session_data_tags: Vec::new(),
-            session_key_tags: Vec::new(),
-        }
-    }
+use derive_builder::Builder;
 
-    /// Sets the protocol compatibility version of the resulting playlist.
-    ///
-    /// If the resulting playlist has tags which requires a compatibility version greater than `version`,
-    /// `finish()` method will fail with an `ErrorKind::InvalidInput` error.
-    ///
-    /// The default is the maximum version among the tags in the playlist.
-    pub fn version(&mut self, version: ProtocolVersion) -> &mut Self {
-        self.version = Some(version);
-        self
-    }
-
-    /// Adds the given tag to the resulting playlist.
-    ///
-    /// If it is forbidden to have multiple instance of the tag, the existing one will be overwritten.
-    pub fn tag<T: Into<MasterPlaylistTag>>(&mut self, tag: T) -> &mut Self {
-        match tag.into() {
-            MasterPlaylistTag::ExtXIndependentSegments(t) => {
-                self.independent_segments_tag = Some(t);
-            }
-            MasterPlaylistTag::ExtXStart(t) => self.start_tag = Some(t),
-            MasterPlaylistTag::ExtXMedia(t) => self.media_tags.push(t),
-            MasterPlaylistTag::ExtXStreamInf(t) => self.stream_inf_tags.push(t),
-            MasterPlaylistTag::ExtXIFrameStreamInf(t) => self.i_frame_stream_inf_tags.push(t),
-            MasterPlaylistTag::ExtXSessionData(t) => self.session_data_tags.push(t),
-            MasterPlaylistTag::ExtXSessionKey(t) => self.session_key_tags.push(t),
-        }
-        self
-    }
-
-    /// Builds a `MasterPlaylist` instance.
-    pub fn finish(self) -> Result<MasterPlaylist> {
-        let required_version = self.required_version();
-        let specified_version = self.version.unwrap_or(required_version);
-        track_assert!(
-            required_version <= specified_version,
-            ErrorKind::InvalidInput,
-            "required_version:{}, specified_version:{}",
-            required_version,
-            specified_version,
-        );
-
-        track!(self.validate_stream_inf_tags())?;
-        track!(self.validate_i_frame_stream_inf_tags())?;
-        track!(self.validate_session_data_tags())?;
-        track!(self.validate_session_key_tags())?;
-
-        Ok(MasterPlaylist {
-            version_tag: ExtXVersion::new(specified_version),
-            independent_segments_tag: self.independent_segments_tag,
-            start_tag: self.start_tag,
-            media_tags: self.media_tags,
-            stream_inf_tags: self.stream_inf_tags,
-            i_frame_stream_inf_tags: self.i_frame_stream_inf_tags,
-            session_data_tags: self.session_data_tags,
-            session_key_tags: self.session_key_tags,
-        })
-    }
-
-    fn required_version(&self) -> ProtocolVersion {
-        iter::empty()
-            .chain(
-                self.independent_segments_tag
-                    .iter()
-                    .map(|t| t.requires_version()),
-            )
-            .chain(self.start_tag.iter().map(|t| t.requires_version()))
-            .chain(self.media_tags.iter().map(|t| t.requires_version()))
-            .chain(self.stream_inf_tags.iter().map(|t| t.requires_version()))
-            .chain(
-                self.i_frame_stream_inf_tags
-                    .iter()
-                    .map(|t| t.requires_version()),
-            )
-            .chain(self.session_data_tags.iter().map(|t| t.requires_version()))
-            .chain(self.session_key_tags.iter().map(|t| t.requires_version()))
-            .max()
-            .expect("Never fails")
-    }
-
-    fn validate_stream_inf_tags(&self) -> Result<()> {
-        let mut has_none_closed_captions = false;
-        for t in &self.stream_inf_tags {
-            if let Some(group_id) = t.audio() {
-                track_assert!(
-                    self.check_media_group(MediaType::Audio, group_id),
-                    ErrorKind::InvalidInput,
-                    "Unmatched audio group: {:?}",
-                    group_id
-                );
-            }
-            if let Some(group_id) = t.video() {
-                track_assert!(
-                    self.check_media_group(MediaType::Video, group_id),
-                    ErrorKind::InvalidInput,
-                    "Unmatched video group: {:?}",
-                    group_id
-                );
-            }
-            if let Some(group_id) = t.subtitles() {
-                track_assert!(
-                    self.check_media_group(MediaType::Subtitles, group_id),
-                    ErrorKind::InvalidInput,
-                    "Unmatched subtitles group: {:?}",
-                    group_id
-                );
-            }
-            match t.closed_captions() {
-                Some(&ClosedCaptions::GroupId(ref group_id)) => {
-                    track_assert!(
-                        self.check_media_group(MediaType::ClosedCaptions, group_id),
-                        ErrorKind::InvalidInput,
-                        "Unmatched closed-captions group: {:?}",
-                        group_id
-                    );
-                }
-                Some(&ClosedCaptions::None) => {
-                    has_none_closed_captions = true;
-                }
-                None => {}
-            }
-        }
-        if has_none_closed_captions {
-            track_assert!(
-                self.stream_inf_tags
-                    .iter()
-                    .all(|t| t.closed_captions() == Some(&ClosedCaptions::None)),
-                ErrorKind::InvalidInput
-            );
-        }
-        Ok(())
-    }
-
-    fn validate_i_frame_stream_inf_tags(&self) -> Result<()> {
-        for t in &self.i_frame_stream_inf_tags {
-            if let Some(group_id) = t.video() {
-                track_assert!(
-                    self.check_media_group(MediaType::Video, group_id),
-                    ErrorKind::InvalidInput,
-                    "Unmatched video group: {:?}",
-                    group_id
-                );
-            }
-        }
-        Ok(())
-    }
-
-    fn validate_session_data_tags(&self) -> Result<()> {
-        let mut set = HashSet::new();
-        for t in &self.session_data_tags {
-            track_assert!(
-                set.insert((t.data_id(), t.language())),
-                ErrorKind::InvalidInput,
-                "Conflict: {}",
-                t
-            );
-        }
-        Ok(())
-    }
-
-    fn validate_session_key_tags(&self) -> Result<()> {
-        let mut set = HashSet::new();
-        for t in &self.session_key_tags {
-            track_assert!(
-                set.insert(t.key()),
-                ErrorKind::InvalidInput,
-                "Conflict: {}",
-                t
-            );
-        }
-        Ok(())
-    }
-
-    fn check_media_group(&self, media_type: MediaType, group_id: &QuotedString) -> bool {
-        self.media_tags
-            .iter()
-            .any(|t| t.media_type() == media_type && t.group_id() == group_id)
-    }
-}
-impl Default for MasterPlaylistBuilder {
-    fn default() -> Self {
-        Self::new()
-    }
-}
+use crate::line::{Line, Lines, Tag};
+use crate::tags::{
+    ExtM3u, ExtXIFrameStreamInf, ExtXIndependentSegments, ExtXMedia, ExtXSessionData,
+    ExtXSessionKey, ExtXStart, ExtXStreamInf, ExtXVersion,
+};
+use crate::types::{ClosedCaptions, MediaType, ProtocolVersion};
+use crate::Error;
 
 /// Master playlist.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Builder)]
+#[builder(build_fn(validate = "Self::validate"))]
+#[builder(setter(into, strip_option))]
 pub struct MasterPlaylist {
+    #[builder(default, setter(name = "version"))]
+    /// Sets the protocol compatibility version of the resulting playlist.
+    ///
+    /// If the resulting playlist has tags which requires a compatibility version greater than
+    /// `version`,
+    /// `build()` method will fail with an `ErrorKind::InvalidInput` error.
+    ///
+    /// The default is the maximum version among the tags in the playlist.
     version_tag: ExtXVersion,
+    #[builder(default)]
+    /// Sets the [ExtXIndependentSegments] tag.
     independent_segments_tag: Option<ExtXIndependentSegments>,
+    #[builder(default)]
+    /// Sets the [ExtXStart] tag.
     start_tag: Option<ExtXStart>,
+    /// Sets the [ExtXMedia] tag.
     media_tags: Vec<ExtXMedia>,
+    /// Sets all [ExtXStreamInf]s.
     stream_inf_tags: Vec<ExtXStreamInf>,
+    /// Sets all [ExtXIFrameStreamInf]s.
     i_frame_stream_inf_tags: Vec<ExtXIFrameStreamInf>,
+    /// Sets all [ExtXSessionData]s.
     session_data_tags: Vec<ExtXSessionData>,
+    /// Sets all [ExtXSessionKey]s.
     session_key_tags: Vec<ExtXSessionKey>,
 }
+
 impl MasterPlaylist {
+    /// Returns a Builder for a MasterPlaylist.
+    pub fn builder() -> MasterPlaylistBuilder {
+        MasterPlaylistBuilder::default()
+    }
+
     /// Returns the `EXT-X-VERSION` tag contained in the playlist.
-    pub fn version_tag(&self) -> ExtXVersion {
+    pub const fn version_tag(&self) -> ExtXVersion {
         self.version_tag
     }
 
     /// Returns the `EXT-X-INDEPENDENT-SEGMENTS` tag contained in the playlist.
-    pub fn independent_segments_tag(&self) -> Option<ExtXIndependentSegments> {
+    pub const fn independent_segments_tag(&self) -> Option<ExtXIndependentSegments> {
         self.independent_segments_tag
     }
 
     /// Returns the `EXT-X-START` tag contained in the playlist.
-    pub fn start_tag(&self) -> Option<ExtXStart> {
+    pub const fn start_tag(&self) -> Option<ExtXStart> {
         self.start_tag
     }
 
@@ -274,6 +91,156 @@ impl MasterPlaylist {
         &self.session_key_tags
     }
 }
+
+impl MasterPlaylistBuilder {
+    fn validate(&self) -> Result<(), String> {
+        let required_version = self.required_version();
+        let specified_version = self
+            .version_tag
+            .unwrap_or(required_version.into())
+            .version();
+
+        if required_version > specified_version {
+            return Err(Error::required_version(required_version, specified_version).to_string());
+        }
+
+        self.validate_stream_inf_tags().map_err(|e| e.to_string())?;
+        self.validate_i_frame_stream_inf_tags()
+            .map_err(|e| e.to_string())?;
+        self.validate_session_data_tags()
+            .map_err(|e| e.to_string())?;
+
+        Ok(())
+    }
+
+    fn required_version(&self) -> ProtocolVersion {
+        iter::empty()
+            .chain(
+                self.independent_segments_tag
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .chain(
+                self.start_tag
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .chain(
+                self.media_tags
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .chain(
+                self.stream_inf_tags
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .chain(
+                self.i_frame_stream_inf_tags
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .chain(
+                self.session_data_tags
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .chain(
+                self.session_key_tags
+                    .iter()
+                    .map(|t| t.iter().map(|t| t.requires_version()))
+                    .flatten(),
+            )
+            .max()
+            .unwrap_or(ProtocolVersion::latest())
+    }
+
+    fn validate_stream_inf_tags(&self) -> crate::Result<()> {
+        if let Some(value) = &self.stream_inf_tags {
+            let mut has_none_closed_captions = false;
+
+            for t in value {
+                if let Some(group_id) = t.audio() {
+                    if !self.check_media_group(MediaType::Audio, group_id) {
+                        return Err(Error::unmatched_group(group_id));
+                    }
+                }
+                if let Some(group_id) = t.video() {
+                    if !self.check_media_group(MediaType::Video, group_id) {
+                        return Err(Error::unmatched_group(group_id));
+                    }
+                }
+                if let Some(group_id) = t.subtitles() {
+                    if !self.check_media_group(MediaType::Subtitles, group_id) {
+                        return Err(Error::unmatched_group(group_id));
+                    }
+                }
+                match t.closed_captions() {
+                    Some(&ClosedCaptions::GroupId(ref group_id)) => {
+                        if !self.check_media_group(MediaType::ClosedCaptions, group_id) {
+                            return Err(Error::unmatched_group(group_id));
+                        }
+                    }
+                    Some(&ClosedCaptions::None) => {
+                        has_none_closed_captions = true;
+                    }
+                    None => {}
+                }
+            }
+            if has_none_closed_captions {
+                if !value
+                    .iter()
+                    .all(|t| t.closed_captions() == Some(&ClosedCaptions::None))
+                {
+                    return Err(Error::invalid_input());
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_i_frame_stream_inf_tags(&self) -> crate::Result<()> {
+        if let Some(value) = &self.i_frame_stream_inf_tags {
+            for t in value {
+                if let Some(group_id) = t.video() {
+                    if !self.check_media_group(MediaType::Video, group_id) {
+                        return Err(Error::unmatched_group(group_id));
+                    }
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn validate_session_data_tags(&self) -> crate::Result<()> {
+        let mut set = HashSet::new();
+        if let Some(value) = &self.session_data_tags {
+            for t in value {
+                if !set.insert((t.data_id(), t.language())) {
+                    return Err(Error::custom(format!("Conflict: {}", t)));
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn check_media_group<T: ToString>(&self, media_type: MediaType, group_id: T) -> bool {
+        if let Some(value) = &self.media_tags {
+            value
+                .iter()
+                .any(|t| t.media_type() == media_type && t.group_id() == &group_id.to_string())
+        } else {
+            false
+        }
+    }
+}
+
 impl fmt::Display for MasterPlaylist {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         writeln!(f, "{}", ExtM3u)?;
@@ -295,33 +262,42 @@ impl fmt::Display for MasterPlaylist {
         for t in &self.session_key_tags {
             writeln!(f, "{}", t)?;
         }
-        if let Some(ref t) = self.independent_segments_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.independent_segments_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.start_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.start_tag {
+            writeln!(f, "{}", value)?;
         }
         Ok(())
     }
 }
+
 impl FromStr for MasterPlaylist {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        let mut builder = MasterPlaylistBuilder::new();
-        for (i, line) in Lines::new(s).enumerate() {
-            match track!(line)? {
-                Line::Blank | Line::Comment(_) => {}
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let mut builder = MasterPlaylist::builder();
+
+        let mut media_tags = vec![];
+        let mut stream_inf_tags = vec![];
+        let mut i_frame_stream_inf_tags = vec![];
+        let mut session_data_tags = vec![];
+        let mut session_key_tags = vec![];
+
+        for (i, line) in input.parse::<Lines>()?.into_iter().enumerate() {
+            match line {
                 Line::Tag(tag) => {
                     if i == 0 {
-                        track_assert_eq!(tag, Tag::ExtM3u(ExtM3u), ErrorKind::InvalidInput);
+                        if tag != Tag::ExtM3u(ExtM3u) {
+                            return Err(Error::invalid_input());
+                        }
                         continue;
                     }
                     match tag {
                         Tag::ExtM3u(_) => {
-                            track_panic!(ErrorKind::InvalidInput);
+                            return Err(Error::invalid_input());
                         }
                         Tag::ExtXVersion(t) => {
-                            track_assert_eq!(builder.version, None, ErrorKind::InvalidInput);
                             builder.version(t.version());
                         }
                         Tag::ExtInf(_)
@@ -337,46 +313,92 @@ impl FromStr for MasterPlaylist {
                         | Tag::ExtXEndList(_)
                         | Tag::ExtXPlaylistType(_)
                         | Tag::ExtXIFramesOnly(_) => {
-                            track_panic!(ErrorKind::InvalidInput, "{}", tag)
+                            return Err(Error::custom(format!(
+                                "This tag isn't allowed in a master playlist: {}",
+                                tag
+                            )));
                         }
                         Tag::ExtXMedia(t) => {
-                            builder.tag(t);
+                            media_tags.push(t);
                         }
                         Tag::ExtXStreamInf(t) => {
-                            builder.tag(t);
+                            stream_inf_tags.push(t);
                         }
                         Tag::ExtXIFrameStreamInf(t) => {
-                            builder.tag(t);
+                            i_frame_stream_inf_tags.push(t);
                         }
                         Tag::ExtXSessionData(t) => {
-                            builder.tag(t);
+                            session_data_tags.push(t);
                         }
                         Tag::ExtXSessionKey(t) => {
-                            builder.tag(t);
+                            session_key_tags.push(t);
                         }
                         Tag::ExtXIndependentSegments(t) => {
-                            track_assert_eq!(
-                                builder.independent_segments_tag,
-                                None,
-                                ErrorKind::InvalidInput
-                            );
-                            builder.tag(t);
+                            builder.independent_segments_tag(t);
                         }
                         Tag::ExtXStart(t) => {
-                            track_assert_eq!(builder.start_tag, None, ErrorKind::InvalidInput);
-                            builder.tag(t);
+                            builder.start_tag(t);
                         }
-                        Tag::Unknown(_) => {
+                        _ => {
                             // [6.3.1. General Client Responsibilities]
                             // > ignore any unrecognized tags.
+                            // TODO: collect custom tags
                         }
                     }
                 }
                 Line::Uri(uri) => {
-                    track_panic!(ErrorKind::InvalidInput, "Unexpected URI: {:?}", uri);
+                    return Err(Error::custom(format!("Unexpected URI: {:?}", uri)));
                 }
             }
         }
-        track!(builder.finish())
+
+        builder.media_tags(media_tags);
+        builder.stream_inf_tags(stream_inf_tags);
+        builder.i_frame_stream_inf_tags(i_frame_stream_inf_tags);
+        builder.session_data_tags(session_data_tags);
+        builder.session_key_tags(session_key_tags);
+
+        builder.build().map_err(Error::builder_error)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parser() {
+        r#"#EXTM3U
+#EXT-X-STREAM-INF:BANDWIDTH=150000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/low/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=240000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/lo_mid/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=440000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/hi_mid/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=640000,RESOLUTION=640x360,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/high/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=64000,CODECS="mp4a.40.5"
+http://example.com/audio/index.m3u8
+"#
+        .parse::<MasterPlaylist>()
+        .unwrap();
+    }
+
+    #[test]
+    fn test_display() {
+        let input = r#"#EXTM3U
+#EXT-X-STREAM-INF:BANDWIDTH=150000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/low/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=240000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/lo_mid/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=440000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/hi_mid/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=640000,RESOLUTION=640x360,CODECS="avc1.42e00a,mp4a.40.2"
+http://example.com/high/index.m3u8
+#EXT-X-STREAM-INF:BANDWIDTH=64000,CODECS="mp4a.40.5"
+http://example.com/audio/index.m3u8
+"#;
+        let playlist = input.parse::<MasterPlaylist>().unwrap();
+        assert_eq!(playlist.to_string(), input);
     }
 }

src/media_playlist.rs

@@ -1,153 +1,137 @@
-use crate::line::{Line, Lines, Tag};
-use crate::media_segment::{MediaSegment, MediaSegmentBuilder};
-use crate::tags::{
-    ExtM3u, ExtXDiscontinuitySequence, ExtXEndList, ExtXIFramesOnly, ExtXIndependentSegments,
-    ExtXMediaSequence, ExtXPlaylistType, ExtXStart, ExtXTargetDuration, ExtXVersion,
-    MediaPlaylistTag,
-};
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::iter;
 use std::str::FromStr;
 use std::time::Duration;
 
-/// Media playlist builder.
-#[derive(Debug, Clone)]
-pub struct MediaPlaylistBuilder {
-    version: Option<ProtocolVersion>,
-    target_duration_tag: Option<ExtXTargetDuration>,
-    media_sequence_tag: Option<ExtXMediaSequence>,
-    discontinuity_sequence_tag: Option<ExtXDiscontinuitySequence>,
-    playlist_type_tag: Option<ExtXPlaylistType>,
-    i_frames_only_tag: Option<ExtXIFramesOnly>,
-    independent_segments_tag: Option<ExtXIndependentSegments>,
-    start_tag: Option<ExtXStart>,
-    end_list_tag: Option<ExtXEndList>,
-    segments: Vec<MediaSegment>,
-    options: MediaPlaylistOptions,
-}
-impl MediaPlaylistBuilder {
-    /// Makes a new `MediaPlaylistBuilder` instance.
-    pub fn new() -> Self {
-        MediaPlaylistBuilder {
-            version: None,
-            target_duration_tag: None,
-            media_sequence_tag: None,
-            discontinuity_sequence_tag: None,
-            playlist_type_tag: None,
-            i_frames_only_tag: None,
-            independent_segments_tag: None,
-            start_tag: None,
-            end_list_tag: None,
-            segments: Vec::new(),
-            options: MediaPlaylistOptions::new(),
-        }
-    }
+use derive_builder::Builder;
 
+use crate::line::{Line, Lines, Tag};
+use crate::media_segment::MediaSegment;
+use crate::tags::{
+    ExtM3u, ExtXDiscontinuitySequence, ExtXEndList, ExtXIFramesOnly, ExtXIndependentSegments,
+    ExtXMediaSequence, ExtXPlaylistType, ExtXStart, ExtXTargetDuration, ExtXVersion,
+};
+use crate::types::ProtocolVersion;
+use crate::Error;
+
+/// Media playlist.
+#[derive(Debug, Clone, Builder)]
+#[builder(build_fn(validate = "Self::validate"))]
+#[builder(setter(into, strip_option))]
+pub struct MediaPlaylist {
     /// Sets the protocol compatibility version of the resulting playlist.
     ///
-    /// If the resulting playlist has tags which requires a compatibility version greater than `version`,
-    /// `finish()` method will fail with an `ErrorKind::InvalidInput` error.
+    /// If the resulting playlist has tags which requires a compatibility
+    /// version greater than `version`,
+    /// `build()` method will fail with an `ErrorKind::InvalidInput` error.
     ///
     /// The default is the maximum version among the tags in the playlist.
-    pub fn version(&mut self, version: ProtocolVersion) -> &mut Self {
-        self.version = Some(version);
-        self
-    }
-
-    /// Sets the given tag to the resulting playlist.
-    pub fn tag<T: Into<MediaPlaylistTag>>(&mut self, tag: T) -> &mut Self {
-        match tag.into() {
-            MediaPlaylistTag::ExtXTargetDuration(t) => self.target_duration_tag = Some(t),
-            MediaPlaylistTag::ExtXMediaSequence(t) => self.media_sequence_tag = Some(t),
-            MediaPlaylistTag::ExtXDiscontinuitySequence(t) => {
-                self.discontinuity_sequence_tag = Some(t)
-            }
-            MediaPlaylistTag::ExtXPlaylistType(t) => self.playlist_type_tag = Some(t),
-            MediaPlaylistTag::ExtXIFramesOnly(t) => self.i_frames_only_tag = Some(t),
-            MediaPlaylistTag::ExtXIndependentSegments(t) => self.independent_segments_tag = Some(t),
-            MediaPlaylistTag::ExtXStart(t) => self.start_tag = Some(t),
-            MediaPlaylistTag::ExtXEndList(t) => self.end_list_tag = Some(t),
-        }
-        self
-    }
-
-    /// Adds a media segment to the resulting playlist.
-    pub fn segment(&mut self, segment: MediaSegment) -> &mut Self {
-        self.segments.push(segment);
-        self
-    }
-
-    /// Sets the options that will be associated to the resulting playlist.
+    #[builder(setter(name = "version"))]
+    version_tag: ExtXVersion,
+    /// Sets the [ExtXTargetDuration] tag.
+    target_duration_tag: ExtXTargetDuration,
+    #[builder(default)]
+    /// Sets the [ExtXMediaSequence] tag.
+    media_sequence_tag: Option<ExtXMediaSequence>,
+    #[builder(default)]
+    /// Sets the [ExtXDiscontinuitySequence] tag.
+    discontinuity_sequence_tag: Option<ExtXDiscontinuitySequence>,
+    #[builder(default)]
+    /// Sets the [ExtXPlaylistType] tag.
+    playlist_type_tag: Option<ExtXPlaylistType>,
+    #[builder(default)]
+    /// Sets the [ExtXIFramesOnly] tag.
+    i_frames_only_tag: Option<ExtXIFramesOnly>,
+    #[builder(default)]
+    /// Sets the [ExtXIndependentSegments] tag.
+    independent_segments_tag: Option<ExtXIndependentSegments>,
+    #[builder(default)]
+    /// Sets the [ExtXStart] tag.
+    start_tag: Option<ExtXStart>,
+    #[builder(default)]
+    /// Sets the [ExtXEndList] tag.
+    end_list_tag: Option<ExtXEndList>,
+    /// Sets all [MediaSegment]s.
+    segments: Vec<MediaSegment>,
+    /// Sets the allowable excess duration of each media segment in the associated playlist.
     ///
-    /// The default value is `MediaPlaylistOptions::default()`.
-    pub fn options(&mut self, options: MediaPlaylistOptions) -> &mut Self {
-        self.options = options;
-        self
-    }
+    /// # Error
+    /// If there is a media segment of which duration exceeds
+    /// `#EXT-X-TARGETDURATION + allowable_excess_duration`,
+    /// the invocation of `MediaPlaylistBuilder::build()` method will fail.
+    ///
+    /// The default value is `Duration::from_secs(0)`.
+    #[builder(default = "Duration::from_secs(0)")]
+    allowable_excess_duration: Duration,
+}
 
-    /// Builds a `MediaPlaylist` instance.
-    pub fn finish(self) -> Result<MediaPlaylist> {
+impl MediaPlaylistBuilder {
+    fn validate(&self) -> Result<(), String> {
         let required_version = self.required_version();
-        let specified_version = self.version.unwrap_or(required_version);
-        track_assert!(
-            required_version <= specified_version,
-            ErrorKind::InvalidInput,
-            "required_version:{}, specified_version:{}",
-            required_version,
-            specified_version,
-        );
+        let specified_version = self
+            .version_tag
+            .unwrap_or(required_version.into())
+            .version();
 
-        let target_duration_tag =
-            track_assert_some!(self.target_duration_tag, ErrorKind::InvalidInput);
-        track!(self.validate_media_segments(target_duration_tag.duration()))?;
+        if required_version > specified_version {
+            return Err(Error::custom(format!(
+                "required_version: {}, specified_version: {}",
+                required_version, specified_version
+            ))
+            .to_string());
+        }
 
-        Ok(MediaPlaylist {
-            version_tag: ExtXVersion::new(specified_version),
-            target_duration_tag,
-            media_sequence_tag: self.media_sequence_tag,
-            discontinuity_sequence_tag: self.discontinuity_sequence_tag,
-            playlist_type_tag: self.playlist_type_tag,
-            i_frames_only_tag: self.i_frames_only_tag,
-            independent_segments_tag: self.independent_segments_tag,
-            start_tag: self.start_tag,
-            end_list_tag: self.end_list_tag,
-            segments: self.segments,
-        })
+        if let Some(target_duration) = &self.target_duration_tag {
+            self.validate_media_segments(target_duration.duration())
+                .map_err(|e| e.to_string())?;
+        }
+
+        Ok(())
     }
 
-    fn validate_media_segments(&self, target_duration: Duration) -> Result<()> {
+    fn validate_media_segments(&self, target_duration: Duration) -> crate::Result<()> {
         let mut last_range_uri = None;
-        for s in &self.segments {
-            // CHECK: `#EXT-X-TARGETDURATION`
-            let segment_duration = s.inf_tag().duration();
-            let rounded_segment_duration = if segment_duration.subsec_nanos() < 500_000_000 {
-                Duration::from_secs(segment_duration.as_secs())
-            } else {
-                Duration::from_secs(segment_duration.as_secs() + 1)
-            };
-            let max_segment_duration = target_duration + self.options.allowable_excess_duration;
-            track_assert!(
-                rounded_segment_duration <= max_segment_duration,
-                ErrorKind::InvalidInput,
-                "Too large segment duration: actual={:?}, max={:?}, target_duration={:?}, uri={:?}",
-                segment_duration,
-                max_segment_duration,
-                target_duration,
-                s.uri()
-            );
-
-            // CHECK: `#EXT-X-BYTE-RANGE`
-            if let Some(tag) = s.byte_range_tag() {
-                if tag.range().start.is_none() {
-                    let last_uri = track_assert_some!(last_range_uri, ErrorKind::InvalidInput);
-                    track_assert_eq!(last_uri, s.uri(), ErrorKind::InvalidInput);
+        if let Some(segments) = &self.segments {
+            for s in segments {
+                // CHECK: `#EXT-X-TARGETDURATION`
+                let segment_duration = s.inf_tag().duration();
+                let rounded_segment_duration = if segment_duration.subsec_nanos() < 500_000_000 {
+                    Duration::from_secs(segment_duration.as_secs())
                 } else {
-                    last_range_uri = Some(s.uri());
+                    Duration::from_secs(segment_duration.as_secs() + 1)
+                };
+
+                let max_segment_duration = {
+                    if let Some(value) = &self.allowable_excess_duration {
+                        target_duration + *value
+                    } else {
+                        target_duration
+                    }
+                };
+
+                if !(rounded_segment_duration <= max_segment_duration) {
+                    return Err(Error::custom(format!(
+                        "Too large segment duration: actual={:?}, max={:?}, target_duration={:?}, uri={:?}",
+                        segment_duration,
+                        max_segment_duration,
+                        target_duration,
+                        s.uri()
+                    )));
+                }
+
+                // CHECK: `#EXT-X-BYTE-RANGE`
+                if let Some(tag) = s.byte_range_tag() {
+                    if tag.to_range().start().is_none() {
+                        let last_uri = last_range_uri.ok_or(Error::invalid_input())?;
+                        if last_uri != s.uri() {
+                            return Err(Error::invalid_input());
+                        }
+                    } else {
+                        last_range_uri = Some(s.uri());
+                    }
+                } else {
+                    last_range_uri = None;
                 }
-            } else {
-                last_range_uri = None;
             }
         }
         Ok(())
@@ -160,89 +144,128 @@ impl MediaPlaylistBuilder {
                     .iter()
                     .map(|t| t.requires_version()),
             )
-            .chain(self.media_sequence_tag.iter().map(|t| t.requires_version()))
-            .chain(
-                self.discontinuity_sequence_tag
-                    .iter()
-                    .map(|t| t.requires_version()),
-            )
-            .chain(self.playlist_type_tag.iter().map(|t| t.requires_version()))
-            .chain(self.i_frames_only_tag.iter().map(|t| t.requires_version()))
-            .chain(
-                self.independent_segments_tag
-                    .iter()
-                    .map(|t| t.requires_version()),
-            )
-            .chain(self.start_tag.iter().map(|t| t.requires_version()))
-            .chain(self.end_list_tag.iter().map(|t| t.requires_version()))
-            .chain(self.segments.iter().map(|s| s.requires_version()))
+            .chain(self.media_sequence_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.discontinuity_sequence_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.playlist_type_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.i_frames_only_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.independent_segments_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.start_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.end_list_tag.iter().map(|t| {
+                if let Some(p) = t {
+                    p.requires_version()
+                } else {
+                    ProtocolVersion::V1
+                }
+            }))
+            .chain(self.segments.iter().map(|t| {
+                t.iter()
+                    .map(|s| s.requires_version())
+                    .max()
+                    .unwrap_or(ProtocolVersion::V1)
+            }))
             .max()
-            .unwrap_or(ProtocolVersion::V1)
+            .unwrap_or(ProtocolVersion::latest())
     }
-}
-impl Default for MediaPlaylistBuilder {
-    fn default() -> Self {
-        Self::new()
+
+    /// Adds a media segment to the resulting playlist.
+    pub fn push_segment<VALUE: Into<MediaSegment>>(&mut self, value: VALUE) -> &mut Self {
+        if let Some(segments) = &mut self.segments {
+            segments.push(value.into());
+        } else {
+            self.segments = Some(vec![value.into()]);
+        }
+        self
+    }
+
+    /// Parse the rest of the [MediaPlaylist] from an m3u8 file.
+    pub fn parse(&mut self, input: &str) -> crate::Result<MediaPlaylist> {
+        parse_media_playlist(input, self)
     }
 }
 
-/// Media playlist.
-#[derive(Debug, Clone)]
-pub struct MediaPlaylist {
-    version_tag: ExtXVersion,
-    target_duration_tag: ExtXTargetDuration,
-    media_sequence_tag: Option<ExtXMediaSequence>,
-    discontinuity_sequence_tag: Option<ExtXDiscontinuitySequence>,
-    playlist_type_tag: Option<ExtXPlaylistType>,
-    i_frames_only_tag: Option<ExtXIFramesOnly>,
-    independent_segments_tag: Option<ExtXIndependentSegments>,
-    start_tag: Option<ExtXStart>,
-    end_list_tag: Option<ExtXEndList>,
-    segments: Vec<MediaSegment>,
-}
 impl MediaPlaylist {
+    /// Creates a [MediaPlaylistBuilder].
+    pub fn builder() -> MediaPlaylistBuilder {
+        MediaPlaylistBuilder::default()
+    }
     /// Returns the `EXT-X-VERSION` tag contained in the playlist.
-    pub fn version_tag(&self) -> ExtXVersion {
+    pub const fn version_tag(&self) -> ExtXVersion {
         self.version_tag
     }
 
     /// Returns the `EXT-X-TARGETDURATION` tag contained in the playlist.
-    pub fn target_duration_tag(&self) -> ExtXTargetDuration {
+    pub const fn target_duration_tag(&self) -> ExtXTargetDuration {
         self.target_duration_tag
     }
 
     /// Returns the `EXT-X-MEDIA-SEQUENCE` tag contained in the playlist.
-    pub fn media_sequence_tag(&self) -> Option<ExtXMediaSequence> {
+    pub const fn media_sequence_tag(&self) -> Option<ExtXMediaSequence> {
         self.media_sequence_tag
     }
 
     /// Returns the `EXT-X-DISCONTINUITY-SEQUENCE` tag contained in the playlist.
-    pub fn discontinuity_sequence_tag(&self) -> Option<ExtXDiscontinuitySequence> {
+    pub const fn discontinuity_sequence_tag(&self) -> Option<ExtXDiscontinuitySequence> {
         self.discontinuity_sequence_tag
     }
 
     /// Returns the `EXT-X-PLAYLIST-TYPE` tag contained in the playlist.
-    pub fn playlist_type_tag(&self) -> Option<ExtXPlaylistType> {
+    pub const fn playlist_type_tag(&self) -> Option<ExtXPlaylistType> {
         self.playlist_type_tag
     }
 
     /// Returns the `EXT-X-I-FRAMES-ONLY` tag contained in the playlist.
-    pub fn i_frames_only_tag(&self) -> Option<ExtXIFramesOnly> {
+    pub const fn i_frames_only_tag(&self) -> Option<ExtXIFramesOnly> {
         self.i_frames_only_tag
     }
 
     /// Returns the `EXT-X-INDEPENDENT-SEGMENTS` tag contained in the playlist.
-    pub fn independent_segments_tag(&self) -> Option<ExtXIndependentSegments> {
+    pub const fn independent_segments_tag(&self) -> Option<ExtXIndependentSegments> {
         self.independent_segments_tag
     }
 
     /// Returns the `EXT-X-START` tag contained in the playlist.
-    pub fn start_tag(&self) -> Option<ExtXStart> {
+    pub const fn start_tag(&self) -> Option<ExtXStart> {
         self.start_tag
     }
 
     /// Returns the `EXT-X-ENDLIST` tag contained in the playlist.
-    pub fn end_list_tag(&self) -> Option<ExtXEndList> {
+    pub const fn end_list_tag(&self) -> Option<ExtXEndList> {
         self.end_list_tag
     }
 
@@ -251,6 +274,7 @@ impl MediaPlaylist {
         &self.segments
     }
 }
+
 impl fmt::Display for MediaPlaylist {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         writeln!(f, "{}", ExtM3u)?;
@@ -258,201 +282,156 @@ impl fmt::Display for MediaPlaylist {
             writeln!(f, "{}", self.version_tag)?;
         }
         writeln!(f, "{}", self.target_duration_tag)?;
-        if let Some(ref t) = self.media_sequence_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.media_sequence_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.discontinuity_sequence_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.discontinuity_sequence_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.playlist_type_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.playlist_type_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.i_frames_only_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.i_frames_only_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.independent_segments_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.independent_segments_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.start_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.start_tag {
+            writeln!(f, "{}", value)?;
         }
         for segment in &self.segments {
             write!(f, "{}", segment)?;
         }
-        if let Some(ref t) = self.end_list_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.end_list_tag {
+            writeln!(f, "{}", value)?;
         }
         Ok(())
     }
 }
-impl FromStr for MediaPlaylist {
-    type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track!(MediaPlaylistOptions::new().parse(s))
-    }
-}
 
-/// Media playlist options.
-#[derive(Debug, Clone)]
-pub struct MediaPlaylistOptions {
-    allowable_excess_duration: Duration,
-}
-impl MediaPlaylistOptions {
-    /// Makes a new `MediaPlaylistOptions` with the default settings.
-    pub fn new() -> Self {
-        MediaPlaylistOptions {
-            allowable_excess_duration: Duration::from_secs(0),
-        }
-    }
+fn parse_media_playlist(
+    input: &str,
+    builder: &mut MediaPlaylistBuilder,
+) -> crate::Result<MediaPlaylist> {
+    let mut segment = MediaSegment::builder();
+    let mut segments = vec![];
 
-    /// Sets the allowable excess duration of each media segment in the associated playlist.
-    ///
-    /// If there is a media segment of which duration exceeds
-    /// `#EXT-X-TARGETDURATION + allowable_excess_duration`,
-    /// the invocation of `MediaPlaylistBuilder::finish()` method will fail.
-    ///
-    /// The default value is `Duration::from_secs(0)`.
-    pub fn allowable_excess_segment_duration(
-        &mut self,
-        allowable_excess_duration: Duration,
-    ) -> &mut Self {
-        self.allowable_excess_duration = allowable_excess_duration;
-        self
-    }
+    let mut has_partial_segment = false;
+    let mut has_discontinuity_tag = false;
+    let mut has_version = false; // m3u8 files without ExtXVersion tags are ProtocolVersion::V1
 
-    /// Parses the given M3U8 text with the specified settings.
-    pub fn parse(&self, m3u8: &str) -> Result<MediaPlaylist> {
-        let mut builder = MediaPlaylistBuilder::new();
-        builder.options(self.clone());
-
-        let mut segment = MediaSegmentBuilder::new();
-        let mut has_partial_segment = false;
-        let mut has_discontinuity_tag = false;
-        for (i, line) in Lines::new(m3u8).enumerate() {
-            match track!(line)? {
-                Line::Blank | Line::Comment(_) => {}
-                Line::Tag(tag) => {
-                    if i == 0 {
-                        track_assert_eq!(tag, Tag::ExtM3u(ExtM3u), ErrorKind::InvalidInput);
-                        continue;
-                    }
-                    match tag {
-                        Tag::ExtM3u(_) => track_panic!(ErrorKind::InvalidInput),
-                        Tag::ExtXVersion(t) => {
-                            track_assert_eq!(builder.version, None, ErrorKind::InvalidInput);
-                            builder.version(t.version());
-                        }
-                        Tag::ExtInf(t) => {
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXByteRange(t) => {
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXDiscontinuity(t) => {
-                            has_discontinuity_tag = true;
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXKey(t) => {
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXMap(t) => {
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXProgramDateTime(t) => {
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXDateRange(t) => {
-                            has_partial_segment = true;
-                            segment.tag(t);
-                        }
-                        Tag::ExtXTargetDuration(t) => {
-                            track_assert_eq!(
-                                builder.target_duration_tag,
-                                None,
-                                ErrorKind::InvalidInput
-                            );
-                            builder.tag(t);
-                        }
-                        Tag::ExtXMediaSequence(t) => {
-                            track_assert_eq!(
-                                builder.media_sequence_tag,
-                                None,
-                                ErrorKind::InvalidInput
-                            );
-                            track_assert!(builder.segments.is_empty(), ErrorKind::InvalidInput);
-                            builder.tag(t);
-                        }
-                        Tag::ExtXDiscontinuitySequence(t) => {
-                            track_assert!(builder.segments.is_empty(), ErrorKind::InvalidInput);
-                            track_assert!(!has_discontinuity_tag, ErrorKind::InvalidInput);
-                            builder.tag(t);
-                        }
-                        Tag::ExtXEndList(t) => {
-                            track_assert_eq!(builder.end_list_tag, None, ErrorKind::InvalidInput);
-                            builder.tag(t);
-                        }
-                        Tag::ExtXPlaylistType(t) => {
-                            track_assert_eq!(
-                                builder.playlist_type_tag,
-                                None,
-                                ErrorKind::InvalidInput
-                            );
-                            builder.tag(t);
-                        }
-                        Tag::ExtXIFramesOnly(t) => {
-                            track_assert_eq!(
-                                builder.i_frames_only_tag,
-                                None,
-                                ErrorKind::InvalidInput
-                            );
-                            builder.tag(t);
-                        }
-                        Tag::ExtXMedia(_)
-                        | Tag::ExtXStreamInf(_)
-                        | Tag::ExtXIFrameStreamInf(_)
-                        | Tag::ExtXSessionData(_)
-                        | Tag::ExtXSessionKey(_) => {
-                            track_panic!(ErrorKind::InvalidInput, "{}", tag)
-                        }
-                        Tag::ExtXIndependentSegments(t) => {
-                            track_assert_eq!(
-                                builder.independent_segments_tag,
-                                None,
-                                ErrorKind::InvalidInput
-                            );
-                            builder.tag(t);
-                        }
-                        Tag::ExtXStart(t) => {
-                            track_assert_eq!(builder.start_tag, None, ErrorKind::InvalidInput);
-                            builder.tag(t);
-                        }
-                        Tag::Unknown(_) => {
-                            // [6.3.1. General Client Responsibilities]
-                            // > ignore any unrecognized tags.
-                        }
+    for (i, line) in input.parse::<Lines>()?.into_iter().enumerate() {
+        match line {
+            Line::Tag(tag) => {
+                if i == 0 {
+                    if tag != Tag::ExtM3u(ExtM3u) {
+                        return Err(Error::custom("m3u8 doesn't start with #EXTM3U"));
                     }
+                    continue;
                 }
-                Line::Uri(uri) => {
-                    segment.uri(uri);
-                    builder.segment(track!(segment.finish())?);
-                    segment = MediaSegmentBuilder::new();
-                    has_partial_segment = false;
+                match tag {
+                    Tag::ExtM3u(_) => return Err(Error::invalid_input()),
+                    Tag::ExtXVersion(t) => {
+                        builder.version(t.version());
+                        has_version = true;
+                    }
+                    Tag::ExtInf(t) => {
+                        has_partial_segment = true;
+                        segment.inf_tag(t);
+                    }
+                    Tag::ExtXByteRange(t) => {
+                        has_partial_segment = true;
+                        segment.byte_range_tag(t);
+                    }
+                    Tag::ExtXDiscontinuity(t) => {
+                        has_discontinuity_tag = true;
+                        has_partial_segment = true;
+                        segment.discontinuity_tag(t);
+                    }
+                    Tag::ExtXKey(t) => {
+                        has_partial_segment = true;
+                        segment.push_key_tag(t);
+                    }
+                    Tag::ExtXMap(t) => {
+                        has_partial_segment = true;
+                        segment.map_tag(t);
+                    }
+                    Tag::ExtXProgramDateTime(t) => {
+                        has_partial_segment = true;
+                        segment.program_date_time_tag(t);
+                    }
+                    Tag::ExtXDateRange(t) => {
+                        has_partial_segment = true;
+                        segment.date_range_tag(t);
+                    }
+                    Tag::ExtXTargetDuration(t) => {
+                        builder.target_duration_tag(t);
+                    }
+                    Tag::ExtXMediaSequence(t) => {
+                        builder.media_sequence_tag(t);
+                    }
+                    Tag::ExtXDiscontinuitySequence(t) => {
+                        if segments.is_empty() {
+                            return Err(Error::invalid_input());
+                        }
+                        if has_discontinuity_tag {
+                            return Err(Error::invalid_input());
+                        }
+                        builder.discontinuity_sequence_tag(t);
+                    }
+                    Tag::ExtXEndList(t) => {
+                        builder.end_list_tag(t);
+                    }
+                    Tag::ExtXPlaylistType(t) => {
+                        builder.playlist_type_tag(t);
+                    }
+                    Tag::ExtXIFramesOnly(t) => {
+                        builder.i_frames_only_tag(t);
+                    }
+                    Tag::ExtXMedia(_)
+                    | Tag::ExtXStreamInf(_)
+                    | Tag::ExtXIFrameStreamInf(_)
+                    | Tag::ExtXSessionData(_)
+                    | Tag::ExtXSessionKey(_) => {
+                        return Err(Error::custom(tag));
+                    }
+                    Tag::ExtXIndependentSegments(t) => {
+                        builder.independent_segments_tag(t);
+                    }
+                    Tag::ExtXStart(t) => {
+                        builder.start_tag(t);
+                    }
+                    Tag::Unknown(_) => {
+                        // [6.3.1. General Client Responsibilities]
+                        // > ignore any unrecognized tags.
+                    }
                 }
             }
+            Line::Uri(uri) => {
+                segment.uri(uri);
+                segments.push(segment.build().map_err(Error::builder_error)?);
+                segment = MediaSegment::builder();
+                has_partial_segment = false;
+            }
         }
-        track_assert!(!has_partial_segment, ErrorKind::InvalidInput);
-        track!(builder.finish())
     }
+    if has_partial_segment {
+        return Err(Error::invalid_input());
+    }
+    if !has_version {
+        builder.version(ProtocolVersion::V1);
+    }
+
+    builder.segments(segments);
+    builder.build().map_err(Error::builder_error)
 }
-impl Default for MediaPlaylistOptions {
-    fn default() -> Self {
-        Self::new()
+
+impl FromStr for MediaPlaylist {
+    type Err = Error;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        parse_media_playlist(input, &mut Self::builder())
     }
 }
 
@@ -462,36 +441,37 @@ mod tests {
 
     #[test]
     fn too_large_segment_duration_test() {
-        let m3u8 = "#EXTM3U\n\
-                    #EXT-X-TARGETDURATION:8\n\
-                    #EXT-X-VERSION:3\n\
-                    #EXTINF:9.009,\n\
-                    http://media.example.com/first.ts\n\
-                    #EXTINF:9.509,\n\
-                    http://media.example.com/second.ts\n\
-                    #EXTINF:3.003,\n\
-                    http://media.example.com/third.ts\n\
-                    #EXT-X-ENDLIST";
+        let playlist = r#"
+        #EXTM3U
+        #EXT-X-TARGETDURATION:8
+        #EXT-X-VERSION:3
+        #EXTINF:9.009,
+        http://media.example.com/first.ts
+        #EXTINF:9.509,
+        http://media.example.com/second.ts
+        #EXTINF:3.003,
+        http://media.example.com/third.ts
+        #EXT-X-ENDLIST"#;
 
         // Error (allowable segment duration = target duration = 8)
-        assert!(m3u8.parse::<MediaPlaylist>().is_err());
+        assert!(playlist.parse::<MediaPlaylist>().is_err());
 
         // Error (allowable segment duration = 9)
-        assert!(MediaPlaylistOptions::new()
-            .allowable_excess_segment_duration(Duration::from_secs(1))
-            .parse(m3u8)
+        assert!(MediaPlaylist::builder()
+            .allowable_excess_duration(Duration::from_secs(1))
+            .parse(playlist)
             .is_err());
 
         // Ok (allowable segment duration = 10)
-        assert!(MediaPlaylistOptions::new()
-            .allowable_excess_segment_duration(Duration::from_secs(2))
-            .parse(m3u8)
-            .is_ok());
+        MediaPlaylist::builder()
+            .allowable_excess_duration(Duration::from_secs(2))
+            .parse(playlist)
+            .unwrap();
     }
 
     #[test]
-    fn empty_m3u8_parse_test() {
-        let m3u8 = "";
-        assert!(m3u8.parse::<MediaPlaylist>().is_err());
+    fn test_empty_playlist() {
+        let playlist = "";
+        assert!(playlist.parse::<MediaPlaylist>().is_err());
     }
 }

src/media_segment.rs

@@ -1,131 +1,97 @@
-use crate::tags::{
-    ExtInf, ExtXByteRange, ExtXDateRange, ExtXDiscontinuity, ExtXKey, ExtXMap, ExtXProgramDateTime,
-    MediaSegmentTag,
-};
-use crate::types::{ProtocolVersion, SingleLineString};
-use crate::{ErrorKind, Result};
 use std::fmt;
 use std::iter;
 
-/// Media segment builder.
-#[derive(Debug, Clone)]
-pub struct MediaSegmentBuilder {
-    key_tags: Vec<ExtXKey>,
-    map_tag: Option<ExtXMap>,
-    byte_range_tag: Option<ExtXByteRange>,
-    date_range_tag: Option<ExtXDateRange>,
-    discontinuity_tag: Option<ExtXDiscontinuity>,
-    program_date_time_tag: Option<ExtXProgramDateTime>,
-    inf_tag: Option<ExtInf>,
-    uri: Option<SingleLineString>,
-}
-impl MediaSegmentBuilder {
-    /// Makes a new `MediaSegmentBuilder` instance.
-    pub fn new() -> Self {
-        MediaSegmentBuilder {
-            key_tags: Vec::new(),
-            map_tag: None,
-            byte_range_tag: None,
-            date_range_tag: None,
-            discontinuity_tag: None,
-            program_date_time_tag: None,
-            inf_tag: None,
-            uri: None,
-        }
-    }
+use derive_builder::Builder;
+use url::Url;
 
-    /// Sets the URI of the resulting media segment.
-    pub fn uri(&mut self, uri: SingleLineString) -> &mut Self {
-        self.uri = Some(uri);
-        self
-    }
-
-    /// Sets the given tag to the resulting media segment.
-    pub fn tag<T: Into<MediaSegmentTag>>(&mut self, tag: T) -> &mut Self {
-        match tag.into() {
-            MediaSegmentTag::ExtInf(t) => self.inf_tag = Some(t),
-            MediaSegmentTag::ExtXByteRange(t) => self.byte_range_tag = Some(t),
-            MediaSegmentTag::ExtXDateRange(t) => self.date_range_tag = Some(t),
-            MediaSegmentTag::ExtXDiscontinuity(t) => self.discontinuity_tag = Some(t),
-            MediaSegmentTag::ExtXKey(t) => self.key_tags.push(t),
-            MediaSegmentTag::ExtXMap(t) => self.map_tag = Some(t),
-            MediaSegmentTag::ExtXProgramDateTime(t) => self.program_date_time_tag = Some(t),
-        }
-        self
-    }
-
-    /// Builds a `MediaSegment` instance.
-    pub fn finish(self) -> Result<MediaSegment> {
-        let uri = track_assert_some!(self.uri, ErrorKind::InvalidInput);
-        let inf_tag = track_assert_some!(self.inf_tag, ErrorKind::InvalidInput);
-        Ok(MediaSegment {
-            key_tags: self.key_tags,
-            map_tag: self.map_tag,
-            byte_range_tag: self.byte_range_tag,
-            date_range_tag: self.date_range_tag,
-            discontinuity_tag: self.discontinuity_tag,
-            program_date_time_tag: self.program_date_time_tag,
-            inf_tag,
-            uri,
-        })
-    }
-}
-impl Default for MediaSegmentBuilder {
-    fn default() -> Self {
-        Self::new()
-    }
-}
+use crate::tags::{
+    ExtInf, ExtXByteRange, ExtXDateRange, ExtXDiscontinuity, ExtXKey, ExtXMap, ExtXProgramDateTime,
+};
+use crate::types::ProtocolVersion;
 
 /// Media segment.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Builder)]
+#[builder(setter(into, strip_option))]
 pub struct MediaSegment {
+    #[builder(default)]
+    /// Sets all [ExtXKey] tags.
     key_tags: Vec<ExtXKey>,
+    #[builder(default)]
+    /// Sets an [ExtXMap] tag.
     map_tag: Option<ExtXMap>,
+    #[builder(default)]
+    /// Sets an [ExtXByteRange] tag.
     byte_range_tag: Option<ExtXByteRange>,
+    #[builder(default)]
+    /// Sets an [ExtXDateRange] tag.
     date_range_tag: Option<ExtXDateRange>,
+    #[builder(default)]
+    /// Sets an [ExtXDiscontinuity] tag.
     discontinuity_tag: Option<ExtXDiscontinuity>,
+    #[builder(default)]
+    /// Sets an [ExtXProgramDateTime] tag.
     program_date_time_tag: Option<ExtXProgramDateTime>,
+    /// Sets an [ExtInf] tag.
     inf_tag: ExtInf,
-    uri: SingleLineString,
+    /// Sets an Uri.
+    uri: Url,
 }
+
+impl MediaSegmentBuilder {
+    /// Pushes an [ExtXKey] tag.
+    pub fn push_key_tag<VALUE: Into<ExtXKey>>(&mut self, value: VALUE) -> &mut Self {
+        if let Some(key_tags) = &mut self.key_tags {
+            key_tags.push(value.into());
+        } else {
+            self.key_tags = Some(vec![value.into()]);
+        }
+        self
+    }
+}
+
 impl fmt::Display for MediaSegment {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        for t in &self.key_tags {
-            writeln!(f, "{}", t)?;
+        for value in &self.key_tags {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.map_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.map_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.byte_range_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.byte_range_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.date_range_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.date_range_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.discontinuity_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.discontinuity_tag {
+            writeln!(f, "{}", value)?;
         }
-        if let Some(ref t) = self.program_date_time_tag {
-            writeln!(f, "{}", t)?;
+        if let Some(value) = &self.program_date_time_tag {
+            writeln!(f, "{}", value)?;
         }
         writeln!(f, "{},", self.inf_tag)?;
         writeln!(f, "{}", self.uri)?;
         Ok(())
     }
 }
+
 impl MediaSegment {
+    /// Creates a [MediaSegmentBuilder].
+    pub fn builder() -> MediaSegmentBuilder {
+        MediaSegmentBuilder::default()
+    }
     /// Returns the URI of the media segment.
-    pub fn uri(&self) -> &SingleLineString {
+    pub const fn uri(&self) -> &Url {
         &self.uri
     }
 
     /// Returns the `EXT-X-INF` tag associated with the media segment.
-    pub fn inf_tag(&self) -> &ExtInf {
+    pub const fn inf_tag(&self) -> &ExtInf {
         &self.inf_tag
     }
 
     /// Returns the `EXT-X-BYTERANGE` tag associated with the media segment.
-    pub fn byte_range_tag(&self) -> Option<ExtXByteRange> {
+    pub const fn byte_range_tag(&self) -> Option<ExtXByteRange> {
         self.byte_range_tag
     }
 
@@ -135,7 +101,7 @@ impl MediaSegment {
     }
 
     /// Returns the `EXT-X-DISCONTINUITY` tag associated with the media segment.
-    pub fn discontinuity_tag(&self) -> Option<ExtXDiscontinuity> {
+    pub const fn discontinuity_tag(&self) -> Option<ExtXDiscontinuity> {
         self.discontinuity_tag
     }
 
@@ -169,6 +135,6 @@ impl MediaSegment {
             )
             .chain(iter::once(self.inf_tag.requires_version()))
             .max()
-            .expect("Never fails")
+            .unwrap_or(ProtocolVersion::V7)
     }
 }

src/tags/basic/m3u.rs

@@ -1,30 +1,36 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.1.1. EXTM3U]
 ///
 /// [4.3.1.1. EXTM3U]: https://tools.ietf.org/html/rfc8216#section-4.3.1.1
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ExtM3u;
+
 impl ExtM3u {
     pub(crate) const PREFIX: &'static str = "#EXTM3U";
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
+
 impl fmt::Display for ExtM3u {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         Self::PREFIX.fmt(f)
     }
 }
+
 impl FromStr for ExtM3u {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert_eq!(s, Self::PREFIX, ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        tag(input, Self::PREFIX)?;
         Ok(ExtM3u)
     }
 }
@@ -34,9 +40,17 @@ mod test {
     use super::*;
 
     #[test]
-    fn extm3u() {
+    fn test_display() {
+        assert_eq!(ExtM3u.to_string(), "#EXTM3U".to_string());
+    }
+
+    #[test]
+    fn test_parser() {
         assert_eq!("#EXTM3U".parse::<ExtM3u>().ok(), Some(ExtM3u));
-        assert_eq!(ExtM3u.to_string(), "#EXTM3U");
+    }
+
+    #[test]
+    fn test_requires_version() {
         assert_eq!(ExtM3u.requires_version(), ProtocolVersion::V1);
     }
 }

src/tags/basic/version.rs

@@ -1,48 +1,59 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.1.2. EXT-X-VERSION]
 ///
 /// [4.3.1.2. EXT-X-VERSION]: https://tools.ietf.org/html/rfc8216#section-4.3.1.2
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ExtXVersion {
-    version: ProtocolVersion,
-}
+pub struct ExtXVersion(ProtocolVersion);
 
 impl ExtXVersion {
     pub(crate) const PREFIX: &'static str = "#EXT-X-VERSION:";
 
     /// Makes a new `ExtXVersion` tag.
-    pub fn new(version: ProtocolVersion) -> Self {
-        ExtXVersion { version }
+    pub const fn new(version: ProtocolVersion) -> Self {
+        Self(version)
     }
 
     /// Returns the protocol compatibility version of the playlist containing this tag.
-    pub fn version(self) -> ProtocolVersion {
-        self.version
+    pub const fn version(&self) -> ProtocolVersion {
+        self.0
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
 
 impl fmt::Display for ExtXVersion {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}{}", Self::PREFIX, self.version)
+        write!(f, "{}{}", Self::PREFIX, self.0)
+    }
+}
+
+impl Default for ExtXVersion {
+    fn default() -> Self {
+        Self(ProtocolVersion::V1)
+    }
+}
+
+impl From<ProtocolVersion> for ExtXVersion {
+    fn from(value: ProtocolVersion) -> Self {
+        Self(value)
     }
 }
 
 impl FromStr for ExtXVersion {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let suffix = s.split_at(Self::PREFIX.len()).1;
-        let version = track!(suffix.parse())?;
-        Ok(ExtXVersion { version })
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let version = tag(input, Self::PREFIX)?.parse()?;
+        Ok(ExtXVersion::new(version))
     }
 }
 
@@ -51,11 +62,34 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_version() {
-        let tag = ExtXVersion::new(ProtocolVersion::V6);
-        assert_eq!("#EXT-X-VERSION:6".parse().ok(), Some(tag));
-        assert_eq!(tag.to_string(), "#EXT-X-VERSION:6");
-        assert_eq!(tag.version(), ProtocolVersion::V6);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+    fn test_display() {
+        assert_eq!(
+            ExtXVersion::new(ProtocolVersion::V6).to_string(),
+            "#EXT-X-VERSION:6"
+        );
+    }
+
+    #[test]
+    fn test_parser() {
+        assert_eq!(
+            "#EXT-X-VERSION:6".parse().ok(),
+            Some(ExtXVersion::new(ProtocolVersion::V6))
+        );
+    }
+
+    #[test]
+    fn test_requires_version() {
+        assert_eq!(
+            ExtXVersion::new(ProtocolVersion::V6).requires_version(),
+            ProtocolVersion::V1
+        );
+    }
+
+    #[test]
+    fn test_version() {
+        assert_eq!(
+            ExtXVersion::new(ProtocolVersion::V6).version(),
+            ProtocolVersion::V6
+        );
     }
 }

src/tags/master_playlist/i_frame_stream_inf.rs

@@ -1,31 +1,60 @@
-use crate::attribute::AttributePairs;
-use crate::types::{DecimalResolution, HdcpLevel, ProtocolVersion, QuotedString};
-use crate::utils::parse_u64;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use getset::{Getters, MutGetters, Setters};
+
+use crate::attribute::AttributePairs;
+use crate::types::{DecimalResolution, HdcpLevel, ProtocolVersion};
+use crate::utils::parse_u64;
+use crate::utils::{quote, tag, unquote};
+use crate::Error;
+
 /// [4.3.4.3. EXT-X-I-FRAME-STREAM-INF]
 ///
 /// [4.3.4.3. EXT-X-I-FRAME-STREAM-INF]: https://tools.ietf.org/html/rfc8216#section-4.3.4.3
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Getters, Setters, MutGetters, Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ExtXIFrameStreamInf {
-    uri: QuotedString,
+    #[get = "pub"]
+    #[set = "pub"]
+    #[get_mut = "pub"]
+    /// The URI, that identifies the associated media playlist.
+    uri: String,
+    #[get = "pub"]
+    #[set = "pub"]
+    #[get_mut = "pub"]
+    /// The peak segment bit rate of the variant stream.
     bandwidth: u64,
+    #[get = "pub"]
+    #[set = "pub"]
+    #[get_mut = "pub"]
+    /// The average segment bit rate of the variant stream.
     average_bandwidth: Option<u64>,
-    codecs: Option<QuotedString>,
+    #[get = "pub"]
+    #[set = "pub"]
+    #[get_mut = "pub"]
+    /// A string that represents the list of codec types contained the variant stream.
+    codecs: Option<String>,
+    /// The optimal pixel resolution at which to display all the video in the variant stream.
     resolution: Option<DecimalResolution>,
+    #[get = "pub"]
+    #[set = "pub"]
+    #[get_mut = "pub"]
+    /// The HDCP level of the variant stream.
     hdcp_level: Option<HdcpLevel>,
-    video: Option<QuotedString>,
+    #[get = "pub"]
+    #[set = "pub"]
+    #[get_mut = "pub"]
+    /// The group identifier for the video in the variant stream.
+    video: Option<String>,
 }
 
 impl ExtXIFrameStreamInf {
     pub(crate) const PREFIX: &'static str = "#EXT-X-I-FRAME-STREAM-INF:";
 
     /// Makes a new `ExtXIFrameStreamInf` tag.
-    pub fn new(uri: QuotedString, bandwidth: u64) -> Self {
+    pub fn new<T: ToString>(uri: T, bandwidth: u64) -> Self {
         ExtXIFrameStreamInf {
-            uri,
+            uri: uri.to_string(),
             bandwidth,
             average_bandwidth: None,
             codecs: None,
@@ -35,43 +64,27 @@ impl ExtXIFrameStreamInf {
         }
     }
 
-    /// Returns the URI that identifies the associated media playlist.
-    pub fn uri(&self) -> &QuotedString {
-        &self.uri
+    /// The optimal pixel resolution at which to display all the video in the variant stream.
+    pub fn resolution(&self) -> Option<(usize, usize)> {
+        if let Some(res) = &self.resolution {
+            Some((res.width(), res.height()))
+        } else {
+            None
+        }
     }
 
-    /// Returns the peak segment bit rate of the variant stream.
-    pub fn bandwidth(&self) -> u64 {
-        self.bandwidth
+    /// Sets the optimal pixel resolution at which to display all the video in the variant stream.
+    pub fn set_resolution(&mut self, width: usize, height: usize) -> &mut Self {
+        if let Some(res) = &mut self.resolution {
+            res.set_width(width);
+            res.set_height(height);
+        } else {
+            self.resolution = Some(DecimalResolution::new(width, height));
+        }
+        self
     }
-
-    /// Returns the average segment bit rate of the variant stream.
-    pub fn average_bandwidth(&self) -> Option<u64> {
-        self.average_bandwidth
-    }
-
-    /// Returns a string that represents the list of codec types contained the variant stream.
-    pub fn codecs(&self) -> Option<&QuotedString> {
-        self.codecs.as_ref()
-    }
-
-    /// Returns the optimal pixel resolution at which to display all the video in the variant stream.
-    pub fn resolution(&self) -> Option<DecimalResolution> {
-        self.resolution
-    }
-
-    /// Returns the HDCP level of the variant stream.
-    pub fn hdcp_level(&self) -> Option<HdcpLevel> {
-        self.hdcp_level
-    }
-
-    /// Returns the group identifier for the video in the variant stream.
-    pub fn video(&self) -> Option<&QuotedString> {
-        self.video.as_ref()
-    }
-
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -79,22 +92,23 @@ impl ExtXIFrameStreamInf {
 impl fmt::Display for ExtXIFrameStreamInf {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", Self::PREFIX)?;
-        write!(f, "URI={}", self.uri)?;
+        write!(f, "URI={}", quote(&self.uri))?;
         write!(f, ",BANDWIDTH={}", self.bandwidth)?;
-        if let Some(ref x) = self.average_bandwidth {
-            write!(f, ",AVERAGE-BANDWIDTH={}", x)?;
+
+        if let Some(value) = &self.average_bandwidth {
+            write!(f, ",AVERAGE-BANDWIDTH={}", value)?;
         }
-        if let Some(ref x) = self.codecs {
-            write!(f, ",CODECS={}", x)?;
+        if let Some(value) = &self.codecs {
+            write!(f, ",CODECS={}", quote(value))?;
         }
-        if let Some(ref x) = self.resolution {
-            write!(f, ",RESOLUTION={}", x)?;
+        if let Some(value) = &self.resolution {
+            write!(f, ",RESOLUTION={}", value)?;
         }
-        if let Some(ref x) = self.hdcp_level {
-            write!(f, ",HDCP-LEVEL={}", x)?;
+        if let Some(value) = &self.hdcp_level {
+            write!(f, ",HDCP-LEVEL={}", value)?;
         }
-        if let Some(ref x) = self.video {
-            write!(f, ",VIDEO={}", x)?;
+        if let Some(value) = &self.video {
+            write!(f, ",VIDEO={}", quote(value))?;
         }
         Ok(())
     }
@@ -102,8 +116,9 @@ impl fmt::Display for ExtXIFrameStreamInf {
 
 impl FromStr for ExtXIFrameStreamInf {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
 
         let mut uri = None;
         let mut bandwidth = None;
@@ -112,17 +127,16 @@ impl FromStr for ExtXIFrameStreamInf {
         let mut resolution = None;
         let mut hdcp_level = None;
         let mut video = None;
-        let attrs = AttributePairs::parse(s.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "URI" => uri = Some(track!(value.parse())?),
-                "BANDWIDTH" => bandwidth = Some(track!(parse_u64(value))?),
-                "AVERAGE-BANDWIDTH" => average_bandwidth = Some(track!(parse_u64(value))?),
-                "CODECS" => codecs = Some(track!(value.parse())?),
-                "RESOLUTION" => resolution = Some(track!(value.parse())?),
-                "HDCP-LEVEL" => hdcp_level = Some(track!(value.parse())?),
-                "VIDEO" => video = Some(track!(value.parse())?),
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "URI" => uri = Some(unquote(value)),
+                "BANDWIDTH" => bandwidth = Some(parse_u64(value)?),
+                "AVERAGE-BANDWIDTH" => average_bandwidth = Some(parse_u64(value)?),
+                "CODECS" => codecs = Some(unquote(value)),
+                "RESOLUTION" => resolution = Some(value.parse()?),
+                "HDCP-LEVEL" => hdcp_level = Some(value.parse()?),
+                "VIDEO" => video = Some(unquote(value)),
                 _ => {
                     // [6.3.1. General Client Responsibilities]
                     // > ignore any attribute/value pair with an unrecognized AttributeName.
@@ -130,8 +144,9 @@ impl FromStr for ExtXIFrameStreamInf {
             }
         }
 
-        let uri = track_assert_some!(uri, ErrorKind::InvalidInput);
-        let bandwidth = track_assert_some!(bandwidth, ErrorKind::InvalidInput);
+        let uri = uri.ok_or(Error::missing_value("URI"))?;
+        let bandwidth = bandwidth.ok_or(Error::missing_value("BANDWIDTH"))?;
+
         Ok(ExtXIFrameStreamInf {
             uri,
             bandwidth,
@@ -149,15 +164,30 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_i_frame_stream_inf() {
-        let tag = ExtXIFrameStreamInf::new(quoted_string("foo"), 1000);
+    fn test_display() {
         let text = r#"#EXT-X-I-FRAME-STREAM-INF:URI="foo",BANDWIDTH=1000"#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+        assert_eq!(ExtXIFrameStreamInf::new("foo", 1000).to_string(), text);
     }
 
-    fn quoted_string(s: &str) -> QuotedString {
-        QuotedString::new(s).unwrap()
+    #[test]
+    fn test_parser() {
+        let text = r#"#EXT-X-I-FRAME-STREAM-INF:URI="foo",BANDWIDTH=1000"#;
+        let i_frame_stream_inf = ExtXIFrameStreamInf::new("foo", 1000);
+        assert_eq!(
+            text.parse::<ExtXIFrameStreamInf>().unwrap(),
+            i_frame_stream_inf.clone()
+        );
+
+        assert_eq!(i_frame_stream_inf.uri(), "foo");
+        assert_eq!(*i_frame_stream_inf.bandwidth(), 1000);
+        // TODO: test all the optional fields
+    }
+
+    #[test]
+    fn test_requires_version() {
+        assert_eq!(
+            ExtXIFrameStreamInf::new("foo", 1000).requires_version(),
+            ProtocolVersion::V1
+        );
     }
 }

src/tags/master_playlist/media.rs

@@ -1,30 +1,31 @@
-use crate::attribute::AttributePairs;
-use crate::types::{InStreamId, MediaType, ProtocolVersion, QuotedString};
-use crate::utils::parse_yes_or_no;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::attribute::AttributePairs;
+use crate::types::{InStreamId, MediaType, ProtocolVersion};
+use crate::utils::{parse_yes_or_no, quote, tag, unquote};
+use crate::Error;
+
 /// `ExtXMedia` builder.
 #[derive(Debug, Clone)]
 pub struct ExtXMediaBuilder {
     media_type: Option<MediaType>,
-    uri: Option<QuotedString>,
-    group_id: Option<QuotedString>,
-    language: Option<QuotedString>,
-    assoc_language: Option<QuotedString>,
-    name: Option<QuotedString>,
+    uri: Option<String>,
+    group_id: Option<String>,
+    language: Option<String>,
+    assoc_language: Option<String>,
+    name: Option<String>,
     default: bool,
     autoselect: Option<bool>,
     forced: Option<bool>,
     instream_id: Option<InStreamId>,
-    characteristics: Option<QuotedString>,
-    channels: Option<QuotedString>,
+    characteristics: Option<String>,
+    channels: Option<String>,
 }
 
 impl ExtXMediaBuilder {
     /// Makes a `ExtXMediaBuilder` instance.
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         ExtXMediaBuilder {
             media_type: None,
             uri: None,
@@ -48,32 +49,32 @@ impl ExtXMediaBuilder {
     }
 
     /// Sets the identifier that specifies the group to which the rendition belongs.
-    pub fn group_id(&mut self, group_id: QuotedString) -> &mut Self {
-        self.group_id = Some(group_id);
+    pub fn group_id<T: ToString>(&mut self, group_id: T) -> &mut Self {
+        self.group_id = Some(group_id.to_string());
         self
     }
 
     /// Sets a human-readable description of the rendition.
-    pub fn name(&mut self, name: QuotedString) -> &mut Self {
-        self.name = Some(name);
+    pub fn name<T: ToString>(&mut self, name: T) -> &mut Self {
+        self.name = Some(name.to_string());
         self
     }
 
     /// Sets the URI that identifies the media playlist.
-    pub fn uri(&mut self, uri: QuotedString) -> &mut Self {
-        self.uri = Some(uri);
+    pub fn uri<T: ToString>(&mut self, uri: T) -> &mut Self {
+        self.uri = Some(uri.to_string());
         self
     }
 
     /// Sets the name of the primary language used in the rendition.
-    pub fn language(&mut self, language: QuotedString) -> &mut Self {
-        self.language = Some(language);
+    pub fn language<T: ToString>(&mut self, language: T) -> &mut Self {
+        self.language = Some(language.to_string());
         self
     }
 
     /// Sets the name of a language associated with the rendition.
-    pub fn assoc_language(&mut self, language: QuotedString) -> &mut Self {
-        self.assoc_language = Some(language);
+    pub fn assoc_language<T: ToString>(&mut self, language: T) -> &mut Self {
+        self.assoc_language = Some(language.to_string());
         self
     }
 
@@ -102,34 +103,51 @@ impl ExtXMediaBuilder {
     }
 
     /// Sets the string that represents uniform type identifiers (UTI).
-    pub fn characteristics(&mut self, characteristics: QuotedString) -> &mut Self {
-        self.characteristics = Some(characteristics);
+    pub fn characteristics<T: ToString>(&mut self, characteristics: T) -> &mut Self {
+        self.characteristics = Some(characteristics.to_string());
         self
     }
 
     /// Sets the string that represents the parameters of the rendition.
-    pub fn channels(&mut self, channels: QuotedString) -> &mut Self {
-        self.channels = Some(channels);
+    pub fn channels<T: ToString>(&mut self, channels: T) -> &mut Self {
+        self.channels = Some(channels.to_string());
         self
     }
 
     /// Builds a `ExtXMedia` instance.
-    pub fn finish(self) -> Result<ExtXMedia> {
-        let media_type = track_assert_some!(self.media_type, ErrorKind::InvalidInput);
-        let group_id = track_assert_some!(self.group_id, ErrorKind::InvalidInput);
-        let name = track_assert_some!(self.name, ErrorKind::InvalidInput);
+    pub fn finish(self) -> crate::Result<ExtXMedia> {
+        let media_type = self
+            .media_type
+            .ok_or(Error::missing_value("self.media_type"))?;
+        let group_id = self.group_id.ok_or(Error::missing_value("self.group_id"))?;
+        let name = self.name.ok_or(Error::missing_value("self.name"))?;
+
         if MediaType::ClosedCaptions == media_type {
-            track_assert_ne!(self.uri, None, ErrorKind::InvalidInput);
-            track_assert!(self.instream_id.is_some(), ErrorKind::InvalidInput);
+            if let None = self.uri {
+                return Err(Error::missing_value("self.uri"));
+            }
+            self.instream_id
+                .ok_or(Error::missing_value("self.instream_id"))?;
         } else {
-            track_assert!(self.instream_id.is_none(), ErrorKind::InvalidInput);
+            if let Some(_) = &self.instream_id {
+                Err(Error::invalid_input())?;
+            }
         }
+
         if self.default && self.autoselect.is_some() {
-            track_assert_eq!(self.autoselect, Some(true), ErrorKind::InvalidInput);
+            if let Some(value) = &self.autoselect {
+                if *value {
+                    Err(Error::invalid_input())?;
+                }
+            }
         }
+
         if MediaType::Subtitles != media_type {
-            track_assert_eq!(self.forced, None, ErrorKind::InvalidInput);
+            if self.forced.is_some() {
+                Err(Error::invalid_input())?;
+            }
         }
+
         Ok(ExtXMedia {
             media_type,
             uri: self.uri,
@@ -159,31 +177,31 @@ impl Default for ExtXMediaBuilder {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ExtXMedia {
     media_type: MediaType,
-    uri: Option<QuotedString>,
-    group_id: QuotedString,
-    language: Option<QuotedString>,
-    assoc_language: Option<QuotedString>,
-    name: QuotedString,
+    uri: Option<String>,
+    group_id: String,
+    language: Option<String>,
+    assoc_language: Option<String>,
+    name: String,
     default: bool,
     autoselect: bool,
     forced: bool,
     instream_id: Option<InStreamId>,
-    characteristics: Option<QuotedString>,
-    channels: Option<QuotedString>,
+    characteristics: Option<String>,
+    channels: Option<String>,
 }
 
 impl ExtXMedia {
     pub(crate) const PREFIX: &'static str = "#EXT-X-MEDIA:";
 
     /// Makes a new `ExtXMedia` tag.
-    pub fn new(media_type: MediaType, group_id: QuotedString, name: QuotedString) -> Self {
+    pub fn new<T: ToString>(media_type: MediaType, group_id: T, name: T) -> Self {
         ExtXMedia {
             media_type,
             uri: None,
-            group_id,
+            group_id: group_id.to_string(),
             language: None,
             assoc_language: None,
-            name,
+            name: name.to_string(),
             default: false,
             autoselect: false,
             forced: false,
@@ -194,65 +212,65 @@ impl ExtXMedia {
     }
 
     /// Returns the type of the media associated with this tag.
-    pub fn media_type(&self) -> MediaType {
+    pub const fn media_type(&self) -> MediaType {
         self.media_type
     }
 
     /// Returns the identifier that specifies the group to which the rendition belongs.
-    pub fn group_id(&self) -> &QuotedString {
+    pub const fn group_id(&self) -> &String {
         &self.group_id
     }
 
     /// Returns a human-readable description of the rendition.
-    pub fn name(&self) -> &QuotedString {
+    pub const fn name(&self) -> &String {
         &self.name
     }
 
     /// Returns the URI that identifies the media playlist.
-    pub fn uri(&self) -> Option<&QuotedString> {
+    pub fn uri(&self) -> Option<&String> {
         self.uri.as_ref()
     }
 
     /// Returns the name of the primary language used in the rendition.
-    pub fn language(&self) -> Option<&QuotedString> {
+    pub fn language(&self) -> Option<&String> {
         self.language.as_ref()
     }
 
     /// Returns the name of a language associated with the rendition.
-    pub fn assoc_language(&self) -> Option<&QuotedString> {
+    pub fn assoc_language(&self) -> Option<&String> {
         self.assoc_language.as_ref()
     }
 
     /// Returns whether this is the default rendition.
-    pub fn default(&self) -> bool {
+    pub const fn default(&self) -> bool {
         self.default
     }
 
     /// Returns whether the client may choose to
     /// play this rendition in the absence of explicit user preference.
-    pub fn autoselect(&self) -> bool {
+    pub const fn autoselect(&self) -> bool {
         self.autoselect
     }
 
     /// Returns whether the rendition contains content that is considered essential to play.
-    pub fn forced(&self) -> bool {
+    pub const fn forced(&self) -> bool {
         self.forced
     }
 
     /// Returns the identifier that specifies a rendition within the segments in the media playlist.
-    pub fn instream_id(&self) -> Option<InStreamId> {
+    pub const fn instream_id(&self) -> Option<InStreamId> {
         self.instream_id
     }
 
     /// Returns a string that represents uniform type identifiers (UTI).
     ///
     /// Each UTI indicates an individual characteristic of the rendition.
-    pub fn characteristics(&self) -> Option<&QuotedString> {
+    pub fn characteristics(&self) -> Option<&String> {
         self.characteristics.as_ref()
     }
 
     /// Returns a string that represents the parameters of the rendition.
-    pub fn channels(&self) -> Option<&QuotedString> {
+    pub fn channels(&self) -> Option<&String> {
         self.channels.as_ref()
     }
 
@@ -273,17 +291,17 @@ impl fmt::Display for ExtXMedia {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", Self::PREFIX)?;
         write!(f, "TYPE={}", self.media_type)?;
-        if let Some(ref x) = self.uri {
-            write!(f, ",URI={}", x)?;
+        if let Some(value) = &self.uri {
+            write!(f, ",URI={}", quote(value))?;
         }
-        write!(f, ",GROUP-ID={}", self.group_id)?;
-        if let Some(ref x) = self.language {
-            write!(f, ",LANGUAGE={}", x)?;
+        write!(f, ",GROUP-ID={}", quote(&self.group_id))?;
+        if let Some(value) = &self.language {
+            write!(f, ",LANGUAGE={}", quote(value))?;
         }
-        if let Some(ref x) = self.assoc_language {
-            write!(f, ",ASSOC-LANGUAGE={}", x)?;
+        if let Some(value) = &self.assoc_language {
+            write!(f, ",ASSOC-LANGUAGE={}", quote(value))?;
         }
-        write!(f, ",NAME={}", self.name)?;
+        write!(f, ",NAME={}", quote(&self.name))?;
         if self.default {
             write!(f, ",DEFAULT=YES")?;
         }
@@ -293,14 +311,14 @@ impl fmt::Display for ExtXMedia {
         if self.forced {
             write!(f, ",FORCED=YES")?;
         }
-        if let Some(ref x) = self.instream_id {
-            write!(f, ",INSTREAM-ID=\"{}\"", x)?;
+        if let Some(value) = &self.instream_id {
+            write!(f, ",INSTREAM-ID={}", quote(value))?;
         }
-        if let Some(ref x) = self.characteristics {
-            write!(f, ",CHARACTERISTICS={}", x)?;
+        if let Some(value) = &self.characteristics {
+            write!(f, ",CHARACTERISTICS={}", quote(value))?;
         }
-        if let Some(ref x) = self.channels {
-            write!(f, ",CHANNELS={}", x)?;
+        if let Some(value) = &self.channels {
+            write!(f, ",CHANNELS={}", quote(value))?;
         }
         Ok(())
     }
@@ -308,50 +326,49 @@ impl fmt::Display for ExtXMedia {
 
 impl FromStr for ExtXMedia {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
 
         let mut builder = ExtXMediaBuilder::new();
-        let attrs = AttributePairs::parse(s.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
                 "TYPE" => {
-                    builder.media_type(track!(value.parse())?);
+                    builder.media_type(value.parse()?);
                 }
                 "URI" => {
-                    builder.uri(track!(value.parse())?);
+                    builder.uri(unquote(value));
                 }
                 "GROUP-ID" => {
-                    builder.group_id(track!(value.parse())?);
+                    builder.group_id(unquote(value));
                 }
                 "LANGUAGE" => {
-                    builder.language(track!(value.parse())?);
+                    builder.language(unquote(value));
                 }
                 "ASSOC-LANGUAGE" => {
-                    builder.assoc_language(track!(value.parse())?);
+                    builder.assoc_language(unquote(value));
                 }
                 "NAME" => {
-                    builder.name(track!(value.parse())?);
+                    builder.name(unquote(value));
                 }
                 "DEFAULT" => {
-                    builder.default(track!(parse_yes_or_no(value))?);
+                    builder.default((parse_yes_or_no(value))?);
                 }
                 "AUTOSELECT" => {
-                    builder.autoselect(track!(parse_yes_or_no(value))?);
+                    builder.autoselect((parse_yes_or_no(value))?);
                 }
                 "FORCED" => {
-                    builder.forced(track!(parse_yes_or_no(value))?);
+                    builder.forced((parse_yes_or_no(value))?);
                 }
                 "INSTREAM-ID" => {
-                    let s: QuotedString = track!(value.parse())?;
-                    builder.instream_id(track!(s.parse())?);
+                    builder.instream_id(unquote(value).parse()?);
                 }
                 "CHARACTERISTICS" => {
-                    builder.characteristics(track!(value.parse())?);
+                    builder.characteristics(unquote(value));
                 }
                 "CHANNELS" => {
-                    builder.channels(track!(value.parse())?);
+                    builder.channels(unquote(value));
                 }
                 _ => {
                     // [6.3.1. General Client Responsibilities]
@@ -359,7 +376,7 @@ impl FromStr for ExtXMedia {
                 }
             }
         }
-        track!(builder.finish())
+        (builder.finish())
     }
 }
 
@@ -369,14 +386,10 @@ mod test {
 
     #[test]
     fn ext_x_media() {
-        let tag = ExtXMedia::new(MediaType::Audio, quoted_string("foo"), quoted_string("bar"));
+        let tag = ExtXMedia::new(MediaType::Audio, "foo", "bar");
         let text = r#"#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="foo",NAME="bar""#;
         assert_eq!(text.parse().ok(), Some(tag.clone()));
         assert_eq!(tag.to_string(), text);
         assert_eq!(tag.requires_version(), ProtocolVersion::V1);
     }
-
-    fn quoted_string(s: &str) -> QuotedString {
-        QuotedString::new(s).unwrap()
-    }
 }

src/tags/master_playlist/session_data.rs

@@ -1,57 +1,64 @@
-use crate::attribute::AttributePairs;
-use crate::types::{ProtocolVersion, QuotedString, SessionData};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use getset::{Getters, MutGetters, Setters};
+
+use crate::attribute::AttributePairs;
+use crate::types::ProtocolVersion;
+use crate::utils::{quote, tag, unquote};
+use crate::Error;
+
+/// Session data.
+///
+/// See: [4.3.4.4. EXT-X-SESSION-DATA]
+///
+/// [4.3.4.4. EXT-X-SESSION-DATA]: https://tools.ietf.org/html/rfc8216#section-4.3.4.4
+#[allow(missing_docs)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum SessionData {
+    Value(String),
+    Uri(String),
+}
+
 /// [4.3.4.4. EXT-X-SESSION-DATA]
 ///
 /// [4.3.4.4. EXT-X-SESSION-DATA]: https://tools.ietf.org/html/rfc8216#section-4.3.4.4
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Getters, MutGetters, Setters, Debug, Clone, PartialEq, Eq, Hash)]
+#[get = "pub"]
+#[set = "pub"]
+#[get_mut = "pub"]
 pub struct ExtXSessionData {
-    data_id: QuotedString,
+    /// The identifier of the data.
+    data_id: String,
+    /// The session data.
     data: SessionData,
-    language: Option<QuotedString>,
+    /// The language of the data.
+    language: Option<String>,
 }
 
 impl ExtXSessionData {
     pub(crate) const PREFIX: &'static str = "#EXT-X-SESSION-DATA:";
 
     /// Makes a new `ExtXSessionData` tag.
-    pub fn new(data_id: QuotedString, data: SessionData) -> Self {
+    pub fn new<T: ToString>(data_id: T, data: SessionData) -> Self {
         ExtXSessionData {
-            data_id,
+            data_id: data_id.to_string(),
             data,
             language: None,
         }
     }
 
     /// Makes a new `ExtXSessionData` with the given language.
-    pub fn with_language(data_id: QuotedString, data: SessionData, language: QuotedString) -> Self {
+    pub fn with_language<T: ToString>(data_id: T, data: SessionData, language: T) -> Self {
         ExtXSessionData {
-            data_id,
+            data_id: data_id.to_string(),
             data,
-            language: Some(language),
+            language: Some(language.to_string()),
         }
     }
 
-    /// Returns the identifier of the data.
-    pub fn data_id(&self) -> &QuotedString {
-        &self.data_id
-    }
-
-    /// Returns the session data.
-    pub fn data(&self) -> &SessionData {
-        &self.data
-    }
-
-    /// Returns the language of the data.
-    pub fn language(&self) -> Option<&QuotedString> {
-        self.language.as_ref()
-    }
-
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -59,13 +66,13 @@ impl ExtXSessionData {
 impl fmt::Display for ExtXSessionData {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", Self::PREFIX)?;
-        write!(f, "DATA-ID={}", self.data_id)?;
-        match self.data {
-            SessionData::Value(ref x) => write!(f, ",VALUE={}", x)?,
-            SessionData::Uri(ref x) => write!(f, ",URI={}", x)?,
+        write!(f, "DATA-ID={}", quote(&self.data_id))?;
+        match &self.data {
+            SessionData::Value(value) => write!(f, ",VALUE={}", quote(value))?,
+            SessionData::Uri(value) => write!(f, ",URI={}", quote(value))?,
         }
-        if let Some(ref x) = self.language {
-            write!(f, ",LANGUAGE={}", x)?;
+        if let Some(value) = &self.language {
+            write!(f, ",LANGUAGE={}", quote(value))?;
         }
         Ok(())
     }
@@ -73,21 +80,21 @@ impl fmt::Display for ExtXSessionData {
 
 impl FromStr for ExtXSessionData {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
 
         let mut data_id = None;
         let mut session_value = None;
         let mut uri = None;
         let mut language = None;
-        let attrs = AttributePairs::parse(s.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "DATA-ID" => data_id = Some(track!(value.parse())?),
-                "VALUE" => session_value = Some(track!(value.parse())?),
-                "URI" => uri = Some(track!(value.parse())?),
-                "LANGUAGE" => language = Some(track!(value.parse())?),
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "DATA-ID" => data_id = Some(unquote(value)),
+                "VALUE" => session_value = Some(unquote(value)),
+                "URI" => uri = Some(unquote(value)),
+                "LANGUAGE" => language = Some(unquote(value)),
                 _ => {
                     // [6.3.1. General Client Responsibilities]
                     // > ignore any attribute/value pair with an unrecognized AttributeName.
@@ -95,15 +102,21 @@ impl FromStr for ExtXSessionData {
             }
         }
 
-        let data_id = track_assert_some!(data_id, ErrorKind::InvalidInput);
-        let data = if let Some(value) = session_value {
-            track_assert_eq!(uri, None, ErrorKind::InvalidInput);
-            SessionData::Value(value)
-        } else if let Some(uri) = uri {
-            SessionData::Uri(uri)
-        } else {
-            track_panic!(ErrorKind::InvalidInput);
+        let data_id = data_id.ok_or(Error::missing_value("EXT-X-DATA-ID"))?;
+        let data = {
+            if let Some(value) = session_value {
+                if uri.is_some() {
+                    return Err(Error::invalid_input());
+                } else {
+                    SessionData::Value(value)
+                }
+            } else if let Some(uri) = uri {
+                SessionData::Uri(uri)
+            } else {
+                return Err(Error::invalid_input());
+            }
         };
+
         Ok(ExtXSessionData {
             data_id,
             data,
@@ -117,35 +130,38 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_session_data() {
-        let tag = ExtXSessionData::new(
-            quoted_string("foo"),
-            SessionData::Value(quoted_string("bar")),
-        );
+    fn test_display() {
+        let tag = ExtXSessionData::new("foo", SessionData::Value("bar".into()));
         let text = r#"#EXT-X-SESSION-DATA:DATA-ID="foo",VALUE="bar""#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
         assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
 
-        let tag =
-            ExtXSessionData::new(quoted_string("foo"), SessionData::Uri(quoted_string("bar")));
+        let tag = ExtXSessionData::new("foo", SessionData::Uri("bar".into()));
         let text = r#"#EXT-X-SESSION-DATA:DATA-ID="foo",URI="bar""#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
         assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
 
-        let tag = ExtXSessionData::with_language(
-            quoted_string("foo"),
-            SessionData::Value(quoted_string("bar")),
-            quoted_string("baz"),
-        );
+        let tag = ExtXSessionData::with_language("foo", SessionData::Value("bar".into()), "baz");
         let text = r#"#EXT-X-SESSION-DATA:DATA-ID="foo",VALUE="bar",LANGUAGE="baz""#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
         assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
     }
 
-    fn quoted_string(s: &str) -> QuotedString {
-        QuotedString::new(s).unwrap()
+    #[test]
+    fn test_parser() {
+        let tag = ExtXSessionData::new("foo", SessionData::Value("bar".into()));
+        let text = r#"#EXT-X-SESSION-DATA:DATA-ID="foo",VALUE="bar""#;
+        assert_eq!(text.parse::<ExtXSessionData>().unwrap(), tag);
+
+        let tag = ExtXSessionData::new("foo", SessionData::Uri("bar".into()));
+        let text = r#"#EXT-X-SESSION-DATA:DATA-ID="foo",URI="bar""#;
+        assert_eq!(text.parse::<ExtXSessionData>().unwrap(), tag);
+
+        let tag = ExtXSessionData::with_language("foo", SessionData::Value("bar".into()), "baz");
+        let text = r#"#EXT-X-SESSION-DATA:DATA-ID="foo",VALUE="bar",LANGUAGE="baz""#;
+        assert_eq!(text.parse::<ExtXSessionData>().unwrap(), tag);
+    }
+
+    #[test]
+    fn test_requires_version() {
+        let tag = ExtXSessionData::new("foo", SessionData::Value("bar".into()));
+        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
     }
 }

src/tags/master_playlist/session_key.rs

@@ -1,75 +1,148 @@
-use crate::types::{DecryptionKey, ProtocolVersion};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
+use std::ops::{Deref, DerefMut};
 use std::str::FromStr;
 
+use url::Url;
+
+use crate::types::{DecryptionKey, EncryptionMethod, ProtocolVersion};
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.4.5. EXT-X-SESSION-KEY]
 ///
 /// [4.3.4.5. EXT-X-SESSION-KEY]: https://tools.ietf.org/html/rfc8216#section-4.3.4.5
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ExtXSessionKey {
-    key: DecryptionKey,
-}
+pub struct ExtXSessionKey(DecryptionKey);
 
 impl ExtXSessionKey {
     pub(crate) const PREFIX: &'static str = "#EXT-X-SESSION-KEY:";
 
-    /// Makes a new `ExtXSessionKey` tag.
-    pub fn new(key: DecryptionKey) -> Self {
-        ExtXSessionKey { key }
-    }
+    /// Makes a new [ExtXSessionKey] tag.
+    /// # Panic
+    /// This method will panic, if the [EncryptionMethod] is None.
+    pub fn new(method: EncryptionMethod, uri: Url) -> Self {
+        if method == EncryptionMethod::None {
+            panic!("The EncryptionMethod is not allowed to be None");
+        }
 
-    /// Returns a decryption key for the playlist.
-    pub fn key(&self) -> &DecryptionKey {
-        &self.key
+        Self(DecryptionKey::new(method, uri))
     }
 
     /// Returns the protocol compatibility version that this tag requires.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::tags::ExtXSessionKey;
+    /// use hls_m3u8::types::{EncryptionMethod, ProtocolVersion};
+    ///
+    /// let mut key = ExtXSessionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// assert_eq!(
+    ///     key.requires_version(),
+    ///     ProtocolVersion::V1
+    /// );
+    /// ```
     pub fn requires_version(&self) -> ProtocolVersion {
-        self.key.requires_version()
+        if self.0.key_format.is_some() | self.0.key_format_versions.is_some() {
+            ProtocolVersion::V5
+        } else if self.0.iv.is_some() {
+            ProtocolVersion::V2
+        } else {
+            ProtocolVersion::V1
+        }
     }
 }
 
 impl fmt::Display for ExtXSessionKey {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}{}", Self::PREFIX, self.key)
+        write!(f, "{}{}", Self::PREFIX, self.0)
     }
 }
 
 impl FromStr for ExtXSessionKey {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let suffix = s.split_at(Self::PREFIX.len()).1;
-        let key = track!(suffix.parse())?;
-        Ok(ExtXSessionKey { key })
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
+        Ok(Self(input.parse()?))
+    }
+}
+
+impl Deref for ExtXSessionKey {
+    type Target = DecryptionKey;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for ExtXSessionKey {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
     }
 }
 
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::types::{EncryptionMethod, InitializationVector, QuotedString};
+    use crate::types::EncryptionMethod;
 
     #[test]
-    fn ext_x_session_key() {
-        let tag = ExtXSessionKey::new(DecryptionKey {
-            method: EncryptionMethod::Aes128,
-            uri: quoted_string("foo"),
-            iv: Some(InitializationVector([
-                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-            ])),
-            key_format: None,
-            key_format_versions: None,
-        });
-        let text =
-            r#"#EXT-X-SESSION-KEY:METHOD=AES-128,URI="foo",IV=0x000102030405060708090a0b0c0d0e0f"#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V2);
+    fn test_display() {
+        let mut key = ExtXSessionKey::new(
+            EncryptionMethod::Aes128,
+            "https://www.example.com/hls-key/key.bin".parse().unwrap(),
+        );
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
+
+        assert_eq!(
+            key.to_string(),
+            "#EXT-X-SESSION-KEY:METHOD=AES-128,\
+             URI=\"https://www.example.com/hls-key/key.bin\",\
+             IV=0x10ef8f758ca555115584bb5b3c687f52"
+                .to_string()
+        );
     }
 
-    fn quoted_string(s: &str) -> QuotedString {
-        QuotedString::new(s).unwrap()
+    #[test]
+    fn test_parser() {
+        assert_eq!(
+            r#"#EXT-X-SESSION-KEY:METHOD=AES-128,URI="https://priv.example.com/key.php?r=52""#
+                .parse::<ExtXSessionKey>()
+                .unwrap(),
+            ExtXSessionKey::new(
+                EncryptionMethod::Aes128,
+                "https://priv.example.com/key.php?r=52".parse().unwrap()
+            )
+        );
+
+        let mut key = ExtXSessionKey::new(
+            EncryptionMethod::Aes128,
+            "https://www.example.com/hls-key/key.bin".parse().unwrap(),
+        );
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
+
+        assert_eq!(
+            "#EXT-X-SESSION-KEY:METHOD=AES-128,\
+             URI=\"https://www.example.com/hls-key/key.bin\",\
+             IV=0X10ef8f758ca555115584bb5b3c687f52"
+                .parse::<ExtXSessionKey>()
+                .unwrap(),
+            key
+        );
+
+        key.set_key_format("baz");
+
+        assert_eq!(
+            r#"#EXT-X-SESSION-KEY:METHOD=AES-128,URI="https://www.example.com/hls-key/key.bin",IV=0x10ef8f758ca555115584bb5b3c687f52,KEYFORMAT="baz""#
+            .parse::<ExtXSessionKey>().unwrap(),
+            key
+        )
     }
 }

src/tags/master_playlist/stream_inf.rs

@@ -1,28 +1,30 @@
+use std::fmt;
+use std::str::FromStr;
+
+use url::Url;
+
 use crate::attribute::AttributePairs;
 use crate::types::{
     ClosedCaptions, DecimalFloatingPoint, DecimalResolution, HdcpLevel, ProtocolVersion,
-    QuotedString, SingleLineString,
 };
-use crate::utils::parse_u64;
-use crate::{Error, ErrorKind, Result};
-use std::fmt;
-use std::str::FromStr;
+use crate::utils::{parse_u64, quote, tag, unquote};
+use crate::Error;
 
 /// [4.3.4.2. EXT-X-STREAM-INF]
 ///
 /// [4.3.4.2. EXT-X-STREAM-INF]: https://tools.ietf.org/html/rfc8216#section-4.3.4.2
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ExtXStreamInf {
-    uri: SingleLineString,
+    uri: Url,
     bandwidth: u64,
     average_bandwidth: Option<u64>,
-    codecs: Option<QuotedString>,
+    codecs: Option<String>,
     resolution: Option<DecimalResolution>,
     frame_rate: Option<DecimalFloatingPoint>,
     hdcp_level: Option<HdcpLevel>,
-    audio: Option<QuotedString>,
-    video: Option<QuotedString>,
-    subtitles: Option<QuotedString>,
+    audio: Option<String>,
+    video: Option<String>,
+    subtitles: Option<String>,
     closed_captions: Option<ClosedCaptions>,
 }
 
@@ -30,7 +32,7 @@ impl ExtXStreamInf {
     pub(crate) const PREFIX: &'static str = "#EXT-X-STREAM-INF:";
 
     /// Makes a new `ExtXStreamInf` tag.
-    pub fn new(uri: SingleLineString, bandwidth: u64) -> Self {
+    pub const fn new(uri: Url, bandwidth: u64) -> Self {
         ExtXStreamInf {
             uri,
             bandwidth,
@@ -47,52 +49,57 @@ impl ExtXStreamInf {
     }
 
     /// Returns the URI that identifies the associated media playlist.
-    pub fn uri(&self) -> &SingleLineString {
+    pub const fn uri(&self) -> &Url {
         &self.uri
     }
 
     /// Returns the peak segment bit rate of the variant stream.
-    pub fn bandwidth(&self) -> u64 {
+    pub const fn bandwidth(&self) -> u64 {
         self.bandwidth
     }
 
     /// Returns the average segment bit rate of the variant stream.
-    pub fn average_bandwidth(&self) -> Option<u64> {
+    pub const fn average_bandwidth(&self) -> Option<u64> {
         self.average_bandwidth
     }
 
     /// Returns a string that represents the list of codec types contained the variant stream.
-    pub fn codecs(&self) -> Option<&QuotedString> {
+    pub fn codecs(&self) -> Option<&String> {
         self.codecs.as_ref()
     }
 
-    /// Returns the optimal pixel resolution at which to display all the video in the variant stream.
-    pub fn resolution(&self) -> Option<DecimalResolution> {
-        self.resolution
+    /// Returns the optimal pixel resolution at which to display all the video in the variant
+    /// stream.
+    pub fn resolution(&self) -> Option<(usize, usize)> {
+        if let Some(res) = &self.resolution {
+            Some((res.width(), res.height()))
+        } else {
+            None
+        }
     }
 
     /// Returns the maximum frame rate for all the video in the variant stream.
-    pub fn frame_rate(&self) -> Option<DecimalFloatingPoint> {
-        self.frame_rate
+    pub fn frame_rate(&self) -> Option<f64> {
+        self.frame_rate.map_or(None, |v| Some(v.as_f64()))
     }
 
     /// Returns the HDCP level of the variant stream.
-    pub fn hdcp_level(&self) -> Option<HdcpLevel> {
+    pub const fn hdcp_level(&self) -> Option<HdcpLevel> {
         self.hdcp_level
     }
 
     /// Returns the group identifier for the audio in the variant stream.
-    pub fn audio(&self) -> Option<&QuotedString> {
+    pub fn audio(&self) -> Option<&String> {
         self.audio.as_ref()
     }
 
     /// Returns the group identifier for the video in the variant stream.
-    pub fn video(&self) -> Option<&QuotedString> {
+    pub fn video(&self) -> Option<&String> {
         self.video.as_ref()
     }
 
     /// Returns the group identifier for the subtitles in the variant stream.
-    pub fn subtitles(&self) -> Option<&QuotedString> {
+    pub fn subtitles(&self) -> Option<&String> {
         self.subtitles.as_ref()
     }
 
@@ -102,7 +109,7 @@ impl ExtXStreamInf {
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -111,32 +118,32 @@ impl fmt::Display for ExtXStreamInf {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", Self::PREFIX)?;
         write!(f, "BANDWIDTH={}", self.bandwidth)?;
-        if let Some(ref x) = self.average_bandwidth {
-            write!(f, ",AVERAGE-BANDWIDTH={}", x)?;
+        if let Some(value) = &self.average_bandwidth {
+            write!(f, ",AVERAGE-BANDWIDTH={}", value)?;
         }
-        if let Some(ref x) = self.codecs {
-            write!(f, ",CODECS={}", x)?;
+        if let Some(value) = &self.resolution {
+            write!(f, ",RESOLUTION={}", value)?;
         }
-        if let Some(ref x) = self.resolution {
-            write!(f, ",RESOLUTION={}", x)?;
+        if let Some(value) = &self.codecs {
+            write!(f, ",CODECS={}", quote(value))?;
         }
-        if let Some(ref x) = self.frame_rate {
-            write!(f, ",FRAME-RATE={:.3}", x.as_f64())?;
+        if let Some(value) = &self.frame_rate {
+            write!(f, ",FRAME-RATE={:.3}", value.as_f64())?;
         }
-        if let Some(ref x) = self.hdcp_level {
-            write!(f, ",HDCP-LEVEL={}", x)?;
+        if let Some(value) = &self.hdcp_level {
+            write!(f, ",HDCP-LEVEL={}", value)?;
         }
-        if let Some(ref x) = self.audio {
-            write!(f, ",AUDIO={}", x)?;
+        if let Some(value) = &self.audio {
+            write!(f, ",AUDIO={}", quote(value))?;
         }
-        if let Some(ref x) = self.video {
-            write!(f, ",VIDEO={}", x)?;
+        if let Some(value) = &self.video {
+            write!(f, ",VIDEO={}", quote(value))?;
         }
-        if let Some(ref x) = self.subtitles {
-            write!(f, ",SUBTITLES={}", x)?;
+        if let Some(value) = &self.subtitles {
+            write!(f, ",SUBTITLES={}", quote(value))?;
         }
-        if let Some(ref x) = self.closed_captions {
-            write!(f, ",CLOSED-CAPTIONS={}", x)?;
+        if let Some(value) = &self.closed_captions {
+            write!(f, ",CLOSED-CAPTIONS={}", value)?;
         }
         write!(f, "\n{}", self.uri)?;
         Ok(())
@@ -145,16 +152,14 @@ impl fmt::Display for ExtXStreamInf {
 
 impl FromStr for ExtXStreamInf {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        let mut lines = s.splitn(2, '\n');
-        let first_line = lines.next().expect("Never fails").trim_end_matches('\r');
-        let second_line = track_assert_some!(lines.next(), ErrorKind::InvalidInput);
 
-        track_assert!(
-            first_line.starts_with(Self::PREFIX),
-            ErrorKind::InvalidInput
-        );
-        let uri = track!(SingleLineString::new(second_line))?;
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let mut lines = input.lines();
+        let first_line = lines.next().ok_or(Error::missing_value("first_line"))?;
+        let uri = lines.next().ok_or(Error::missing_value("second_line"))?;
+
+        let first_line = tag(first_line, Self::PREFIX)?;
+
         let mut bandwidth = None;
         let mut average_bandwidth = None;
         let mut codecs = None;
@@ -165,29 +170,30 @@ impl FromStr for ExtXStreamInf {
         let mut video = None;
         let mut subtitles = None;
         let mut closed_captions = None;
-        let attrs = AttributePairs::parse(first_line.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "BANDWIDTH" => bandwidth = Some(track!(parse_u64(value))?),
-                "AVERAGE-BANDWIDTH" => average_bandwidth = Some(track!(parse_u64(value))?),
-                "CODECS" => codecs = Some(track!(value.parse())?),
-                "RESOLUTION" => resolution = Some(track!(value.parse())?),
-                "FRAME-RATE" => frame_rate = Some(track!(value.parse())?),
-                "HDCP-LEVEL" => hdcp_level = Some(track!(value.parse())?),
-                "AUDIO" => audio = Some(track!(value.parse())?),
-                "VIDEO" => video = Some(track!(value.parse())?),
-                "SUBTITLES" => subtitles = Some(track!(value.parse())?),
-                "CLOSED-CAPTIONS" => closed_captions = Some(track!(value.parse())?),
+
+        for (key, value) in first_line.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "BANDWIDTH" => bandwidth = Some((parse_u64(value))?),
+                "AVERAGE-BANDWIDTH" => average_bandwidth = Some((parse_u64(value))?),
+                "CODECS" => codecs = Some(unquote(value)),
+                "RESOLUTION" => resolution = Some((value.parse())?),
+                "FRAME-RATE" => frame_rate = Some((value.parse())?),
+                "HDCP-LEVEL" => hdcp_level = Some((value.parse())?),
+                "AUDIO" => audio = Some(unquote(value)),
+                "VIDEO" => video = Some(unquote(value)),
+                "SUBTITLES" => subtitles = Some(unquote(value)),
+                "CLOSED-CAPTIONS" => closed_captions = Some((value.parse())?),
                 _ => {
                     // [6.3.1. General Client Responsibilities]
                     // > ignore any attribute/value pair with an unrecognized AttributeName.
                 }
             }
         }
-        let bandwidth = track_assert_some!(bandwidth, ErrorKind::InvalidInput);
+
+        let bandwidth = bandwidth.ok_or(Error::missing_value("EXT-X-BANDWIDTH"))?;
+
         Ok(ExtXStreamInf {
-            uri,
+            uri: uri.parse()?,
             bandwidth,
             average_bandwidth,
             codecs,
@@ -207,11 +213,30 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_stream_inf() {
-        let tag = ExtXStreamInf::new(SingleLineString::new("foo").unwrap(), 1000);
-        let text = "#EXT-X-STREAM-INF:BANDWIDTH=1000\nfoo";
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+    fn test_parser() {
+        let stream_inf = "#EXT-X-STREAM-INF:BANDWIDTH=1000\nhttp://www.example.com"
+            .parse::<ExtXStreamInf>()
+            .unwrap();
+
+        assert_eq!(
+            stream_inf,
+            ExtXStreamInf::new("http://www.example.com".parse().unwrap(), 1000)
+        );
+    }
+
+    #[test]
+    fn test_requires_version() {
+        assert_eq!(
+            ProtocolVersion::V1,
+            ExtXStreamInf::new("http://www.example.com".parse().unwrap(), 1000).requires_version()
+        );
+    }
+
+    #[test]
+    fn test_display() {
+        assert_eq!(
+            ExtXStreamInf::new("http://www.example.com".parse().unwrap(), 1000).to_string(),
+            "#EXT-X-STREAM-INF:BANDWIDTH=1000\nhttp://www.example.com/".to_string()
+        );
     }
 }

src/tags/media_playlist/discontinuity_sequence.rs

@@ -1,8 +1,8 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
-use trackable::error::ErrorKindExt;
+
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
 
 /// [4.3.3.3. EXT-X-DISCONTINUITY-SEQUENCE]
 ///
@@ -16,18 +16,18 @@ impl ExtXDiscontinuitySequence {
     pub(crate) const PREFIX: &'static str = "#EXT-X-DISCONTINUITY-SEQUENCE:";
 
     /// Makes a new `ExtXDiscontinuitySequence` tag.
-    pub fn new(seq_num: u64) -> Self {
+    pub const fn new(seq_num: u64) -> Self {
         ExtXDiscontinuitySequence { seq_num }
     }
 
     /// Returns the discontinuity sequence number of
     /// the first media segment that appears in the associated playlist.
-    pub fn seq_num(self) -> u64 {
+    pub const fn seq_num(self) -> u64 {
         self.seq_num
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -39,11 +39,11 @@ impl fmt::Display for ExtXDiscontinuitySequence {
 }
 
 impl FromStr for ExtXDiscontinuitySequence {
-    type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let seq_num = may_invalid!(s.split_at(Self::PREFIX.len()).1.parse())?;
-        Ok(ExtXDiscontinuitySequence { seq_num })
+    type Err = crate::Error;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let seq_num = tag(input, Self::PREFIX)?.parse().unwrap(); // TODO!
+        Ok(Self::new(seq_num))
     }
 }
 

src/tags/media_playlist/end_list.rs

@@ -1,8 +1,10 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.3.4. EXT-X-ENDLIST]
 ///
 /// [4.3.3.4. EXT-X-ENDLIST]: https://tools.ietf.org/html/rfc8216#section-4.3.3.4
@@ -12,19 +14,22 @@ impl ExtXEndList {
     pub(crate) const PREFIX: &'static str = "#EXT-X-ENDLIST";
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
+
 impl fmt::Display for ExtXEndList {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         Self::PREFIX.fmt(f)
     }
 }
+
 impl FromStr for ExtXEndList {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert_eq!(s, Self::PREFIX, ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        tag(input, Self::PREFIX)?;
         Ok(ExtXEndList)
     }
 }

src/tags/media_playlist/i_frames_only.rs

@@ -1,8 +1,10 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.3.6. EXT-X-I-FRAMES-ONLY]
 ///
 /// [4.3.3.6. EXT-X-I-FRAMES-ONLY]: https://tools.ietf.org/html/rfc8216#section-4.3.3.6
@@ -13,7 +15,7 @@ impl ExtXIFramesOnly {
     pub(crate) const PREFIX: &'static str = "#EXT-X-I-FRAMES-ONLY";
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(self) -> ProtocolVersion {
         ProtocolVersion::V4
     }
 }
@@ -26,8 +28,9 @@ impl fmt::Display for ExtXIFramesOnly {
 
 impl FromStr for ExtXIFramesOnly {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert_eq!(s, Self::PREFIX, ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        tag(input, Self::PREFIX)?;
         Ok(ExtXIFramesOnly)
     }
 }

src/tags/media_playlist/media_sequence.rs

@@ -1,8 +1,9 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
-use trackable::error::ErrorKindExt;
+
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
 
 /// [4.3.3.2. EXT-X-MEDIA-SEQUENCE]
 ///
@@ -16,17 +17,17 @@ impl ExtXMediaSequence {
     pub(crate) const PREFIX: &'static str = "#EXT-X-MEDIA-SEQUENCE:";
 
     /// Makes a new `ExtXMediaSequence` tag.
-    pub fn new(seq_num: u64) -> Self {
+    pub const fn new(seq_num: u64) -> Self {
         ExtXMediaSequence { seq_num }
     }
 
     /// Returns the sequence number of the first media segment that appears in the associated playlist.
-    pub fn seq_num(self) -> u64 {
+    pub const fn seq_num(self) -> u64 {
         self.seq_num
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -39,10 +40,11 @@ impl fmt::Display for ExtXMediaSequence {
 
 impl FromStr for ExtXMediaSequence {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let seq_num = may_invalid!(s.split_at(Self::PREFIX.len()).1.parse())?;
-        Ok(ExtXMediaSequence { seq_num })
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let seq_num = tag(input, Self::PREFIX)?.parse()?;
+
+        Ok(ExtXMediaSequence::new(seq_num))
     }
 }
 

src/tags/media_playlist/playlist_type.rs

@@ -1,48 +1,62 @@
-use crate::types::{PlaylistType, ProtocolVersion};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
-use trackable::error::ErrorKindExt;
 
-/// [4.3.3.5. EXT-X-PLAYLIST-TYPE]
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
+/// [4.3.3.5. EXT-X-PLAYLIST-TYPE](https://tools.ietf.org/html/rfc8216#section-4.3.3.5)
 ///
-/// [4.3.3.5. EXT-X-PLAYLIST-TYPE]: https://tools.ietf.org/html/rfc8216#section-4.3.3.5
+/// The EXT-X-PLAYLIST-TYPE tag provides mutability information about the
+/// Media Playlist. It applies to the entire Media Playlist.
+/// It is OPTIONAL. Its format is:
+///
+/// ```text
+/// #EXT-X-PLAYLIST-TYPE:<type-enum>
+/// ```
+///
+/// # Note
+/// If the EXT-X-PLAYLIST-TYPE tag is omitted from a Media Playlist, the
+/// Playlist can be updated according to the rules in Section 6.2.1 with
+/// no additional restrictions.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ExtXPlaylistType {
-    playlist_type: PlaylistType,
+pub enum ExtXPlaylistType {
+    /// If the ExtXPlaylistType is Event, Media Segments can only be added to
+    /// the end of the Media Playlist.
+    Event,
+    /// If the ExtXPlaylistType is Video On Demand (Vod),
+    /// the Media Playlist cannot change.
+    Vod,
 }
 
 impl ExtXPlaylistType {
     pub(crate) const PREFIX: &'static str = "#EXT-X-PLAYLIST-TYPE:";
 
-    /// Makes a new `ExtXPlaylistType` tag.
-    pub fn new(playlist_type: PlaylistType) -> Self {
-        ExtXPlaylistType { playlist_type }
-    }
-
-    /// Returns the type of the associated media playlist.
-    pub fn playlist_type(self) -> PlaylistType {
-        self.playlist_type
-    }
-
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
 
 impl fmt::Display for ExtXPlaylistType {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}{}", Self::PREFIX, self.playlist_type)
+        match &self {
+            Self::Event => write!(f, "{}EVENT", Self::PREFIX),
+            Self::Vod => write!(f, "{}VOD", Self::PREFIX),
+        }
     }
 }
 
 impl FromStr for ExtXPlaylistType {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let playlist_type = may_invalid!(s.split_at(Self::PREFIX.len()).1.parse())?;
-        Ok(ExtXPlaylistType { playlist_type })
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
+        match input {
+            "EVENT" => Ok(Self::Event),
+            "VOD" => Ok(Self::Vod),
+            _ => Err(Error::custom(format!("Unknown playlist type: {:?}", input))),
+        }
     }
 }
 
@@ -51,11 +65,48 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_playlist_type() {
-        let tag = ExtXPlaylistType::new(PlaylistType::Vod);
-        let text = "#EXT-X-PLAYLIST-TYPE:VOD";
-        assert_eq!(text.parse().ok(), Some(tag));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+    fn test_parser() {
+        assert_eq!(
+            "#EXT-X-PLAYLIST-TYPE:VOD"
+                .parse::<ExtXPlaylistType>()
+                .unwrap(),
+            ExtXPlaylistType::Vod,
+        );
+
+        assert_eq!(
+            "#EXT-X-PLAYLIST-TYPE:EVENT"
+                .parse::<ExtXPlaylistType>()
+                .unwrap(),
+            ExtXPlaylistType::Event,
+        );
+
+        assert!("#EXT-X-PLAYLIST-TYPE:H"
+            .parse::<ExtXPlaylistType>()
+            .is_err());
+    }
+
+    #[test]
+    fn test_display() {
+        assert_eq!(
+            "#EXT-X-PLAYLIST-TYPE:VOD".to_string(),
+            ExtXPlaylistType::Vod.to_string(),
+        );
+
+        assert_eq!(
+            "#EXT-X-PLAYLIST-TYPE:EVENT".to_string(),
+            ExtXPlaylistType::Event.to_string(),
+        );
+    }
+
+    #[test]
+    fn test_requires_version() {
+        assert_eq!(
+            ExtXPlaylistType::Vod.requires_version(),
+            ProtocolVersion::V1
+        );
+        assert_eq!(
+            ExtXPlaylistType::Event.requires_version(),
+            ProtocolVersion::V1
+        );
     }
 }

src/tags/media_playlist/target_duration.rs

@@ -1,14 +1,15 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 use std::time::Duration;
-use trackable::error::ErrorKindExt;
+
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
 
 /// [4.3.3.1. EXT-X-TARGETDURATION]
 ///
 /// [4.3.3.1. EXT-X-TARGETDURATION]: https://tools.ietf.org/html/rfc8216#section-4.3.3.1
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
 pub struct ExtXTargetDuration {
     duration: Duration,
 }
@@ -19,18 +20,18 @@ impl ExtXTargetDuration {
     /// Makes a new `ExtXTargetduration` tag.
     ///
     /// Note that the nanoseconds part of the `duration` will be discarded.
-    pub fn new(duration: Duration) -> Self {
+    pub const fn new(duration: Duration) -> Self {
         let duration = Duration::from_secs(duration.as_secs());
         ExtXTargetDuration { duration }
     }
 
     /// Returns the maximum media segment duration in the associated playlist.
-    pub fn duration(&self) -> Duration {
+    pub const fn duration(&self) -> Duration {
         self.duration
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -43,11 +44,11 @@ impl fmt::Display for ExtXTargetDuration {
 
 impl FromStr for ExtXTargetDuration {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let duration = may_invalid!(s.split_at(Self::PREFIX.len()).1.parse())?;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?.parse()?;
         Ok(ExtXTargetDuration {
-            duration: Duration::from_secs(duration),
+            duration: Duration::from_secs(input),
         })
     }
 }

src/tags/media_segment/byte_range.rs

@@ -1,48 +1,96 @@
-use crate::types::{ByteRange, ProtocolVersion};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
+use std::ops::Deref;
 use std::str::FromStr;
-use trackable::error::ErrorKindExt;
+
+use crate::types::{ByteRange, ProtocolVersion};
+use crate::utils::tag;
+use crate::Error;
 
 /// [4.3.2.2. EXT-X-BYTERANGE]
 ///
 /// [4.3.2.2. EXT-X-BYTERANGE]: https://tools.ietf.org/html/rfc8216#section-4.3.2.2
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ExtXByteRange {
-    range: ByteRange,
-}
+pub struct ExtXByteRange(ByteRange);
 
 impl ExtXByteRange {
     pub(crate) const PREFIX: &'static str = "#EXT-X-BYTERANGE:";
 
     /// Makes a new `ExtXByteRange` tag.
-    pub fn new(range: ByteRange) -> Self {
-        ExtXByteRange { range }
+    /// # Example
+    /// ```
+    /// use hls_m3u8::tags::ExtXByteRange;
+    ///
+    /// let byte_range = ExtXByteRange::new(20, Some(5));
+    /// ```
+    pub const fn new(length: usize, start: Option<usize>) -> Self {
+        Self(ByteRange::new(length, start))
     }
 
-    /// Returns the range of the associated media segment.
-    pub fn range(&self) -> ByteRange {
-        self.range
+    /// Converts the [ExtXByteRange] to a [ByteRange].
+    /// # Example
+    /// ```
+    /// use hls_m3u8::tags::ExtXByteRange;
+    /// use hls_m3u8::types::ByteRange;
+    ///
+    /// let byte_range = ExtXByteRange::new(20, Some(5));
+    /// let range: ByteRange = byte_range.to_range();
+    /// ```
+    pub const fn to_range(&self) -> ByteRange {
+        self.0
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    /// # Example
+    /// ```
+    /// use hls_m3u8::tags::ExtXByteRange;
+    /// use hls_m3u8::types::ProtocolVersion;
+    ///
+    /// let byte_range = ExtXByteRange::new(20, Some(5));
+    /// assert_eq!(byte_range.requires_version(), ProtocolVersion::V4);
+    /// ```
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V4
     }
 }
 
+impl Deref for ExtXByteRange {
+    type Target = ByteRange;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 impl fmt::Display for ExtXByteRange {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}{}", Self::PREFIX, self.range)
+        write!(f, "{}", Self::PREFIX)?;
+        write!(f, "{}", self.0)?;
+        Ok(())
     }
 }
 
 impl FromStr for ExtXByteRange {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let range = may_invalid!(s.split_at(Self::PREFIX.len()).1.parse())?;
-        Ok(ExtXByteRange { range })
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
+
+        let tokens = input.splitn(2, '@').collect::<Vec<_>>();
+        if tokens.is_empty() {
+            return Err(Error::invalid_input());
+        }
+
+        let length = tokens[0].parse()?;
+
+        let start = {
+            let mut result = None;
+            if tokens.len() == 2 {
+                result = Some(tokens[1].parse()?);
+            }
+            result
+        };
+
+        Ok(ExtXByteRange::new(length, start))
     }
 }
 
@@ -51,21 +99,40 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_byterange() {
-        let tag = ExtXByteRange::new(ByteRange {
-            length: 3,
-            start: None,
-        });
-        assert_eq!("#EXT-X-BYTERANGE:3".parse().ok(), Some(tag));
-        assert_eq!(tag.to_string(), "#EXT-X-BYTERANGE:3");
-        assert_eq!(tag.requires_version(), ProtocolVersion::V4);
+    fn test_display() {
+        let byte_range = ExtXByteRange::new(0, Some(5));
+        assert_eq!(byte_range.to_string(), "#EXT-X-BYTERANGE:0@5".to_string());
 
-        let tag = ExtXByteRange::new(ByteRange {
-            length: 3,
-            start: Some(5),
-        });
-        assert_eq!("#EXT-X-BYTERANGE:3@5".parse().ok(), Some(tag));
-        assert_eq!(tag.to_string(), "#EXT-X-BYTERANGE:3@5");
-        assert_eq!(tag.requires_version(), ProtocolVersion::V4);
+        let byte_range = ExtXByteRange::new(99999, Some(2));
+        assert_eq!(
+            byte_range.to_string(),
+            "#EXT-X-BYTERANGE:99999@2".to_string()
+        );
+
+        let byte_range = ExtXByteRange::new(99999, None);
+        assert_eq!(byte_range.to_string(), "#EXT-X-BYTERANGE:99999".to_string());
+    }
+
+    #[test]
+    fn test_parse() {
+        let byte_range = ExtXByteRange::new(99999, Some(2));
+        assert_eq!(
+            byte_range,
+            "#EXT-X-BYTERANGE:99999@2".parse::<ExtXByteRange>().unwrap()
+        );
+
+        let byte_range = ExtXByteRange::new(99999, None);
+        assert_eq!(
+            byte_range,
+            "#EXT-X-BYTERANGE:99999".parse::<ExtXByteRange>().unwrap()
+        );
+    }
+
+    #[test]
+    fn test_deref() {
+        let byte_range = ExtXByteRange::new(0, Some(22));
+
+        assert_eq!(*byte_range.length(), 0);
+        assert_eq!(*byte_range.start(), Some(22));
     }
 }

src/tags/media_segment/date_range.rs

@@ -1,37 +1,75 @@
-use crate::attribute::AttributePairs;
-use crate::types::{DecimalFloatingPoint, ProtocolVersion, QuotedString};
-use crate::{Error, ErrorKind, Result};
 use std::collections::BTreeMap;
 use std::fmt;
 use std::str::FromStr;
 use std::time::Duration;
 
+use chrono::{DateTime, FixedOffset};
+use getset::{Getters, MutGetters, Setters};
+
+use crate::attribute::AttributePairs;
+use crate::types::{DecimalFloatingPoint, ProtocolVersion};
+use crate::utils::{quote, tag, unquote};
+use crate::Error;
+
 /// [4.3.2.7.  EXT-X-DATERANGE]
 ///
 /// [4.3.2.7.  EXT-X-DATERANGE]: https://tools.ietf.org/html/rfc8216#section-4.3.2.7
 ///
 /// TODO: Implement properly
 #[allow(missing_docs)]
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Getters, MutGetters, Setters)]
+#[get = "pub"]
+#[set = "pub"]
+#[get_mut = "pub"]
 pub struct ExtXDateRange {
-    pub id: QuotedString,
-    pub class: Option<QuotedString>,
-    pub start_date: QuotedString,
-    pub end_date: Option<QuotedString>,
-    pub duration: Option<Duration>,
-    pub planned_duration: Option<Duration>,
-    pub scte35_cmd: Option<QuotedString>,
-    pub scte35_out: Option<QuotedString>,
-    pub scte35_in: Option<QuotedString>,
-    pub end_on_next: bool,
-    pub client_attributes: BTreeMap<String, String>,
+    /// A string that uniquely identifies a Date Range in the Playlist.
+    /// This attribute is REQUIRED.
+    id: String,
+    /// A client-defined string that specifies some set of attributes and their associated value
+    /// semantics. All Date Ranges with the same CLASS attribute value MUST adhere to these
+    /// semantics. This attribute is OPTIONAL.
+    class: Option<String>,
+    /// The date at which the Date Range begins. This attribute is REQUIRED.
+    start_date: DateTime<FixedOffset>,
+    /// The date at which the Date Range ends. It MUST be equal to or later than the value of the
+    /// START-DATE attribute.  This attribute is OPTIONAL.
+    end_date: Option<DateTime<FixedOffset>>,
+    /// The duration of the Date Range. It MUST NOT be negative. A single
+    /// instant in time (e.g., crossing a finish line) SHOULD be
+    /// represented with a duration of 0.  This attribute is OPTIONAL.
+    duration: Option<Duration>,
+    /// The expected duration of the Date Range. It MUST NOT be negative. This
+    /// attribute SHOULD be used to indicate the expected duration of a
+    /// Date Range whose actual duration is not yet known.
+    /// It is OPTIONAL.
+    planned_duration: Option<Duration>,
+    ///
+    scte35_cmd: Option<String>,
+    ///
+    scte35_out: Option<String>,
+    ///
+    scte35_in: Option<String>,
+    /// This attribute indicates that the end of the range containing it is equal to the
+    /// START-DATE of its Following Range. The Following Range is the
+    /// Date Range of the same CLASS, that has the earliest START-DATE
+    /// after the START-DATE of the range in question. This attribute is
+    /// OPTIONAL.
+    end_on_next: bool,
+    /// The "X-" prefix defines a namespace reserved for client-defined
+    /// attributes. The client-attribute MUST be a legal AttributeName.
+    /// Clients SHOULD use a reverse-DNS syntax when defining their own
+    /// attribute names to avoid collisions. The attribute value MUST be
+    /// a quoted-string, a hexadecimal-sequence, or a decimal-floating-
+    /// point. An example of a client-defined attribute is X-COM-EXAMPLE-
+    /// AD-ID="XYZ123". These attributes are OPTIONAL.
+    client_attributes: BTreeMap<String, String>,
 }
 
 impl ExtXDateRange {
     pub(crate) const PREFIX: &'static str = "#EXT-X-DATERANGE:";
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -39,13 +77,13 @@ impl ExtXDateRange {
 impl fmt::Display for ExtXDateRange {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", Self::PREFIX)?;
-        write!(f, "ID={}", self.id)?;
-        if let Some(ref x) = self.class {
-            write!(f, ",CLASS={}", x)?;
+        write!(f, "ID={}", quote(&self.id))?;
+        if let Some(value) = &self.class {
+            write!(f, ",CLASS={}", quote(value))?;
         }
-        write!(f, ",START-DATE={}", self.start_date)?;
-        if let Some(ref x) = self.end_date {
-            write!(f, ",END-DATE={}", x)?;
+        write!(f, ",START-DATE={}", quote(&self.start_date))?;
+        if let Some(value) = &self.end_date {
+            write!(f, ",END-DATE={}", quote(value))?;
         }
         if let Some(x) = self.duration {
             write!(f, ",DURATION={}", DecimalFloatingPoint::from_duration(x))?;
@@ -57,14 +95,14 @@ impl fmt::Display for ExtXDateRange {
                 DecimalFloatingPoint::from_duration(x)
             )?;
         }
-        if let Some(ref x) = self.scte35_cmd {
-            write!(f, ",SCTE35-CMD={}", x)?;
+        if let Some(value) = &self.scte35_cmd {
+            write!(f, ",SCTE35-CMD={}", quote(value))?;
         }
-        if let Some(ref x) = self.scte35_out {
-            write!(f, ",SCTE35-OUT={}", x)?;
+        if let Some(value) = &self.scte35_out {
+            write!(f, ",SCTE35-OUT={}", quote(value))?;
         }
-        if let Some(ref x) = self.scte35_in {
-            write!(f, ",SCTE35-IN={}", x)?;
+        if let Some(value) = &self.scte35_in {
+            write!(f, ",SCTE35-IN={}", quote(value))?;
         }
         if self.end_on_next {
             write!(f, ",END-ON-NEXT=YES",)?;
@@ -78,8 +116,9 @@ impl fmt::Display for ExtXDateRange {
 
 impl FromStr for ExtXDateRange {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
 
         let mut id = None;
         let mut class = None;
@@ -91,28 +130,30 @@ impl FromStr for ExtXDateRange {
         let mut scte35_out = None;
         let mut scte35_in = None;
         let mut end_on_next = false;
+
         let mut client_attributes = BTreeMap::new();
-        let attrs = AttributePairs::parse(s.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "ID" => id = Some(track!(value.parse())?),
-                "CLASS" => class = Some(track!(value.parse())?),
-                "START-DATE" => start_date = Some(track!(value.parse())?),
-                "END-DATE" => end_date = Some(track!(value.parse())?),
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "ID" => id = Some(unquote(value)),
+                "CLASS" => class = Some(unquote(value)),
+                "START-DATE" => start_date = Some(unquote(value)),
+                "END-DATE" => end_date = Some(unquote(value).parse()?),
                 "DURATION" => {
-                    let seconds: DecimalFloatingPoint = track!(value.parse())?;
+                    let seconds: DecimalFloatingPoint = (value.parse())?;
                     duration = Some(seconds.to_duration());
                 }
                 "PLANNED-DURATION" => {
-                    let seconds: DecimalFloatingPoint = track!(value.parse())?;
+                    let seconds: DecimalFloatingPoint = (value.parse())?;
                     planned_duration = Some(seconds.to_duration());
                 }
-                "SCTE35-CMD" => scte35_cmd = Some(track!(value.parse())?),
-                "SCTE35-OUT" => scte35_out = Some(track!(value.parse())?),
-                "SCTE35-IN" => scte35_in = Some(track!(value.parse())?),
+                "SCTE35-CMD" => scte35_cmd = Some(unquote(value)),
+                "SCTE35-OUT" => scte35_out = Some(unquote(value)),
+                "SCTE35-IN" => scte35_in = Some(unquote(value)),
                 "END-ON-NEXT" => {
-                    track_assert_eq!(value, "YES", ErrorKind::InvalidInput);
+                    if value != "YES" {
+                        return Err(Error::invalid_input());
+                    }
                     end_on_next = true;
                 }
                 _ => {
@@ -126,10 +167,15 @@ impl FromStr for ExtXDateRange {
             }
         }
 
-        let id = track_assert_some!(id, ErrorKind::InvalidInput);
-        let start_date = track_assert_some!(start_date, ErrorKind::InvalidInput);
+        let id = id.ok_or(Error::missing_value("EXT-X-ID"))?;
+        let start_date = start_date
+            .ok_or(Error::missing_value("EXT-X-START-DATE"))?
+            .parse()?;
+
         if end_on_next {
-            track_assert!(class.is_some(), ErrorKind::InvalidInput);
+            if class.is_none() {
+                return Err(Error::invalid_input());
+            }
         }
         Ok(ExtXDateRange {
             id,

src/tags/media_segment/discontinuity.rs

@@ -1,30 +1,36 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::{Error, Result};
+
 /// [4.3.2.3. EXT-X-DISCONTINUITY]
 ///
 /// [4.3.2.3. EXT-X-DISCONTINUITY]: https://tools.ietf.org/html/rfc8216#section-4.3.2.3
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ExtXDiscontinuity;
+
 impl ExtXDiscontinuity {
     pub(crate) const PREFIX: &'static str = "#EXT-X-DISCONTINUITY";
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
+
 impl fmt::Display for ExtXDiscontinuity {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         Self::PREFIX.fmt(f)
     }
 }
+
 impl FromStr for ExtXDiscontinuity {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert_eq!(s, Self::PREFIX, ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self> {
+        tag(input, Self::PREFIX)?;
         Ok(ExtXDiscontinuity)
     }
 }

src/tags/media_segment/inf.rs

@@ -1,24 +1,60 @@
-use crate::types::{DecimalFloatingPoint, ProtocolVersion, SingleLineString};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 use std::time::Duration;
-use trackable::error::ErrorKindExt;
 
-/// [4.3.2.1. EXTINF]
+use crate::types::{DecimalFloatingPoint, ProtocolVersion};
+use crate::utils::tag;
+use crate::Error;
+
+/// [4.3.2.1. EXTINF](https://tools.ietf.org/html/rfc8216#section-4.3.2.1)
 ///
-/// [4.3.2.1. EXTINF]: https://tools.ietf.org/html/rfc8216#section-4.3.2.1
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+/// The [ExtInf] tag specifies the duration of a [Media Segment].  It applies
+/// only to the next [Media Segment]. This tag is REQUIRED for each [Media Segment].
+///
+/// Its format is:
+/// ```text
+/// #EXTINF:<duration>,[<title>]
+/// ```
+/// The title is an optional informative title about the [Media Segment].
+///
+/// [Media Segment]: crate::media_segment::MediaSegment
+///
+/// # Examples
+/// Parsing from a String:
+/// ```
+/// use std::time::Duration;
+/// use hls_m3u8::tags::ExtInf;
+///
+/// let ext_inf = "#EXTINF:8,".parse::<ExtInf>().expect("Failed to parse tag!");
+///
+/// assert_eq!(ext_inf.duration(), Duration::from_secs(8));
+/// assert_eq!(ext_inf.title(), None);
+/// ```
+///
+/// Converting to a String:
+/// ```
+/// use std::time::Duration;
+/// use hls_m3u8::tags::ExtInf;
+///
+/// let ext_inf = ExtInf::with_title(
+///     Duration::from_millis(88),
+///     "title"
+/// );
+///
+/// assert_eq!(ext_inf.duration(), Duration::from_millis(88));
+/// assert_eq!(ext_inf.to_string(), "#EXTINF:0.088,title".to_string());
+/// ```
+#[derive(Default, Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct ExtInf {
     duration: Duration,
-    title: Option<SingleLineString>,
+    title: Option<String>,
 }
 
 impl ExtInf {
     pub(crate) const PREFIX: &'static str = "#EXTINF:";
 
     /// Makes a new `ExtInf` tag.
-    pub fn new(duration: Duration) -> Self {
+    pub const fn new(duration: Duration) -> Self {
         ExtInf {
             duration,
             title: None,
@@ -26,20 +62,20 @@ impl ExtInf {
     }
 
     /// Makes a new `ExtInf` tag with the given title.
-    pub fn with_title(duration: Duration, title: SingleLineString) -> Self {
+    pub fn with_title<T: ToString>(duration: Duration, title: T) -> Self {
         ExtInf {
             duration,
-            title: Some(title),
+            title: Some(title.to_string()),
         }
     }
 
     /// Returns the duration of the associated media segment.
-    pub fn duration(&self) -> Duration {
+    pub const fn duration(&self) -> Duration {
         self.duration
     }
 
     /// Returns the title of the associated media segment.
-    pub fn title(&self) -> Option<&SingleLineString> {
+    pub fn title(&self) -> Option<&String> {
         self.title.as_ref()
     }
 
@@ -59,10 +95,10 @@ impl fmt::Display for ExtInf {
 
         let duration = (self.duration.as_secs() as f64)
             + (f64::from(self.duration.subsec_nanos()) / 1_000_000_000.0);
-        write!(f, "{}", duration)?;
+        write!(f, "{},", duration)?;
 
-        if let Some(ref title) = self.title {
-            write!(f, ",{}", title)?;
+        if let Some(value) = &self.title {
+            write!(f, "{}", value)?;
         }
         Ok(())
     }
@@ -70,45 +106,114 @@ impl fmt::Display for ExtInf {
 
 impl FromStr for ExtInf {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let mut tokens = s.split_at(Self::PREFIX.len()).1.splitn(2, ',');
 
-        let seconds: DecimalFloatingPoint =
-            may_invalid!(tokens.next().expect("Never fails").parse())?;
-        let duration = seconds.to_duration();
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
+        dbg!(&input);
+        let tokens = input.splitn(2, ',').collect::<Vec<_>>();
 
-        let title = if let Some(title) = tokens.next() {
-            Some(track!(SingleLineString::new(title))?)
-        } else {
-            None
+        if tokens.len() == 0 {
+            return Err(Error::custom(format!(
+                "failed to parse #EXTINF tag, couldn't split input: {:?}",
+                input
+            )));
+        }
+
+        let duration = tokens[0].parse::<DecimalFloatingPoint>()?.to_duration();
+
+        let title = {
+            if tokens.len() >= 2 {
+                if tokens[1].trim().is_empty() {
+                    None
+                } else {
+                    Some(tokens[1].to_string())
+                }
+            } else {
+                None
+            }
         };
+
         Ok(ExtInf { duration, title })
     }
 }
 
+impl From<Duration> for ExtInf {
+    fn from(value: Duration) -> Self {
+        Self::new(value)
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
 
     #[test]
-    fn extinf() {
-        let tag = ExtInf::new(Duration::from_secs(5));
-        assert_eq!("#EXTINF:5".parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), "#EXTINF:5");
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
-
-        let tag = ExtInf::with_title(
-            Duration::from_secs(5),
-            SingleLineString::new("foo").unwrap(),
+    fn test_display() {
+        assert_eq!(
+            "#EXTINF:5,".to_string(),
+            ExtInf::new(Duration::from_secs(5)).to_string()
         );
-        assert_eq!("#EXTINF:5,foo".parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), "#EXTINF:5,foo");
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+        assert_eq!(
+            "#EXTINF:5.5,".to_string(),
+            ExtInf::new(Duration::from_millis(5500)).to_string()
+        );
+        assert_eq!(
+            "#EXTINF:5.5,title".to_string(),
+            ExtInf::with_title(Duration::from_millis(5500), "title").to_string()
+        );
+        assert_eq!(
+            "#EXTINF:5,title".to_string(),
+            ExtInf::with_title(Duration::from_secs(5), "title").to_string()
+        );
+    }
 
-        let tag = ExtInf::new(Duration::from_millis(1234));
-        assert_eq!("#EXTINF:1.234".parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), "#EXTINF:1.234");
-        assert_eq!(tag.requires_version(), ProtocolVersion::V3);
+    #[test]
+    fn test_parser() {
+        // #EXTINF:<duration>,[<title>]
+        assert_eq!(
+            "#EXTINF:5".parse::<ExtInf>().unwrap(),
+            ExtInf::new(Duration::from_secs(5))
+        );
+        assert_eq!(
+            "#EXTINF:5,".parse::<ExtInf>().unwrap(),
+            ExtInf::new(Duration::from_secs(5))
+        );
+        assert_eq!(
+            "#EXTINF:5.5".parse::<ExtInf>().unwrap(),
+            ExtInf::new(Duration::from_millis(5500))
+        );
+        assert_eq!(
+            "#EXTINF:5.5,".parse::<ExtInf>().unwrap(),
+            ExtInf::new(Duration::from_millis(5500))
+        );
+        assert_eq!(
+            "#EXTINF:5.5,title".parse::<ExtInf>().unwrap(),
+            ExtInf::with_title(Duration::from_millis(5500), "title")
+        );
+        assert_eq!(
+            "#EXTINF:5,title".parse::<ExtInf>().unwrap(),
+            ExtInf::with_title(Duration::from_secs(5), "title")
+        );
+    }
+
+    #[test]
+    fn test_title() {
+        assert_eq!(ExtInf::new(Duration::from_secs(5)).title(), None);
+        assert_eq!(
+            ExtInf::with_title(Duration::from_secs(5), "title").title(),
+            Some(&"title".to_string())
+        );
+    }
+
+    #[test]
+    fn test_requires_version() {
+        assert_eq!(
+            ExtInf::new(Duration::from_secs(4)).requires_version(),
+            ProtocolVersion::V1
+        );
+        assert_eq!(
+            ExtInf::new(Duration::from_millis(4400)).requires_version(),
+            ProtocolVersion::V3
+        );
     }
 }

src/tags/media_segment/key.rs

@@ -1,130 +1,157 @@
-use crate::attribute::AttributePairs;
-use crate::types::{DecryptionKey, ProtocolVersion};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
+use std::ops::{Deref, DerefMut};
 use std::str::FromStr;
 
+use url::Url;
+
+use crate::types::{DecryptionKey, EncryptionMethod};
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.2.4. EXT-X-KEY]
 ///
 /// [4.3.2.4. EXT-X-KEY]: https://tools.ietf.org/html/rfc8216#section-4.3.2.4
+/// # Note
+/// In case of an empty key (`EncryptionMethod::None`), all attributes will be ignored.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ExtXKey {
-    key: Option<DecryptionKey>,
-}
+pub struct ExtXKey(DecryptionKey);
 
 impl ExtXKey {
     pub(crate) const PREFIX: &'static str = "#EXT-X-KEY:";
 
     /// Makes a new `ExtXKey` tag.
-    pub fn new(key: DecryptionKey) -> Self {
-        ExtXKey { key: Some(key) }
+    /// # Example
+    /// ```
+    /// use url::Url;
+    ///
+    /// use hls_m3u8::tags::ExtXKey;
+    /// use hls_m3u8::types::EncryptionMethod;
+    ///
+    /// let key = ExtXKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "#EXT-X-KEY:METHOD=AES-128,URI=\"https://www.example.com/\""
+    /// );
+    /// ```
+    pub const fn new(method: EncryptionMethod, uri: Url) -> Self {
+        Self(DecryptionKey::new(method, uri))
     }
 
     /// Makes a new `ExtXKey` tag without a decryption key.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::tags::ExtXKey;
     ///
-    /// This tag has the `METHDO=NONE` attribute.
-    pub fn new_without_key() -> Self {
-        ExtXKey { key: None }
+    /// let key = ExtXKey::empty();
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "#EXT-X-KEY:METHOD=NONE"
+    /// );
+    /// ```
+    pub const fn empty() -> Self {
+        Self(DecryptionKey {
+            method: EncryptionMethod::None,
+            uri: None,
+            iv: None,
+            key_format: None,
+            key_format_versions: None,
+        })
     }
 
-    /// Returns the decryption key for the following media segments and media initialization sections.
-    pub fn key(&self) -> Option<&DecryptionKey> {
-        self.key.as_ref()
-    }
-
-    /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
-        self.key
-            .as_ref()
-            .map_or(ProtocolVersion::V1, |k| k.requires_version())
-    }
-}
-
-impl fmt::Display for ExtXKey {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", Self::PREFIX)?;
-        if let Some(ref key) = self.key {
-            write!(f, "{}", key)?;
-        } else {
-            write!(f, "METHOD=NONE")?;
-        }
-        Ok(())
+    /// Returns whether the [EncryptionMethod] is [None](EncryptionMethod::None).
+    /// # Example
+    /// ```
+    /// use hls_m3u8::tags::ExtXKey;
+    /// use hls_m3u8::types::EncryptionMethod;
+    ///
+    /// let key = ExtXKey::empty();
+    ///
+    /// assert_eq!(
+    ///     key.method() == EncryptionMethod::None,
+    ///     key.is_empty()
+    /// );
+    /// ```
+    pub fn is_empty(&self) -> bool {
+        self.0.method() == EncryptionMethod::None
     }
 }
 
 impl FromStr for ExtXKey {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let suffix = s.split_at(Self::PREFIX.len()).1;
 
-        if AttributePairs::parse(suffix).any(|a| a.as_ref().ok() == Some(&("METHOD", "NONE"))) {
-            for attr in AttributePairs::parse(suffix) {
-                let (key, _) = track!(attr)?;
-                track_assert_ne!(key, "URI", ErrorKind::InvalidInput);
-                track_assert_ne!(key, "IV", ErrorKind::InvalidInput);
-                track_assert_ne!(key, "KEYFORMAT", ErrorKind::InvalidInput);
-                track_assert_ne!(key, "KEYFORMATVERSIONS", ErrorKind::InvalidInput);
-            }
-            Ok(ExtXKey { key: None })
-        } else {
-            let key = track!(suffix.parse())?;
-            Ok(ExtXKey { key: Some(key) })
-        }
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
+        Ok(Self(input.parse()?))
+    }
+}
+
+impl fmt::Display for ExtXKey {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}{}", Self::PREFIX, self.0)
+    }
+}
+
+impl Deref for ExtXKey {
+    type Target = DecryptionKey;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for ExtXKey {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
     }
 }
 
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::types::{EncryptionMethod, InitializationVector, QuotedString};
+    use crate::types::EncryptionMethod;
 
     #[test]
-    fn ext_x_key() {
-        let tag = ExtXKey::new_without_key();
-        let text = "#EXT-X-KEY:METHOD=NONE";
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+    fn test_display() {
+        assert_eq!(
+            ExtXKey::empty().to_string(),
+            "#EXT-X-KEY:METHOD=NONE".to_string()
+        );
 
-        let tag = ExtXKey::new(DecryptionKey {
-            method: EncryptionMethod::Aes128,
-            uri: QuotedString::new("foo").unwrap(),
-            iv: None,
-            key_format: None,
-            key_format_versions: None,
-        });
-        let text = r#"#EXT-X-KEY:METHOD=AES-128,URI="foo""#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+        let mut key = ExtXKey::empty();
+        // it is expected, that all attributes will be ignored in an empty key!
+        key.set_key_format("hi");
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
+        key.set_uri("https://www.example.com".parse().unwrap());
+        key.set_key_format_versions("1/2/3");
 
-        let tag = ExtXKey::new(DecryptionKey {
-            method: EncryptionMethod::Aes128,
-            uri: QuotedString::new("foo").unwrap(),
-            iv: Some(InitializationVector([
-                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-            ])),
-            key_format: None,
-            key_format_versions: None,
-        });
-        let text = r#"#EXT-X-KEY:METHOD=AES-128,URI="foo",IV=0x000102030405060708090a0b0c0d0e0f"#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V2);
+        assert_eq!(key.to_string(), "#EXT-X-KEY:METHOD=NONE".to_string());
+    }
 
-        let tag = ExtXKey::new(DecryptionKey {
-            method: EncryptionMethod::Aes128,
-            uri: QuotedString::new("foo").unwrap(),
-            iv: Some(InitializationVector([
-                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
-            ])),
-            key_format: Some(QuotedString::new("baz").unwrap()),
-            key_format_versions: None,
-        });
-        let text = r#"#EXT-X-KEY:METHOD=AES-128,URI="foo",IV=0x000102030405060708090a0b0c0d0e0f,KEYFORMAT="baz""#;
-        assert_eq!(text.parse().ok(), Some(tag.clone()));
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V5);
+    #[test]
+    fn test_parser() {
+        assert_eq!(
+            r#"#EXT-X-KEY:METHOD=AES-128,URI="https://priv.example.com/key.php?r=52""#
+                .parse::<ExtXKey>()
+                .unwrap(),
+            ExtXKey::new(
+                EncryptionMethod::Aes128,
+                "https://priv.example.com/key.php?r=52".parse().unwrap()
+            )
+        );
+
+        let mut key = ExtXKey::new(
+            EncryptionMethod::Aes128,
+            "https://www.example.com/hls-key/key.bin".parse().unwrap(),
+        );
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
     }
 }

src/tags/media_segment/map.rs

@@ -1,15 +1,17 @@
-use crate::attribute::AttributePairs;
-use crate::types::{ByteRange, ProtocolVersion, QuotedString};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::attribute::AttributePairs;
+use crate::types::{ByteRange, ProtocolVersion};
+use crate::utils::{quote, tag, unquote};
+use crate::Error;
+
 /// [4.3.2.5. EXT-X-MAP]
 ///
 /// [4.3.2.5. EXT-X-MAP]: https://tools.ietf.org/html/rfc8216#section-4.3.2.5
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ExtXMap {
-    uri: QuotedString,
+    uri: String,
     range: Option<ByteRange>,
 }
 
@@ -17,30 +19,33 @@ impl ExtXMap {
     pub(crate) const PREFIX: &'static str = "#EXT-X-MAP:";
 
     /// Makes a new `ExtXMap` tag.
-    pub fn new(uri: QuotedString) -> Self {
-        ExtXMap { uri, range: None }
+    pub fn new<T: ToString>(uri: T) -> Self {
+        ExtXMap {
+            uri: uri.to_string(),
+            range: None,
+        }
     }
 
     /// Makes a new `ExtXMap` tag with the given range.
-    pub fn with_range(uri: QuotedString, range: ByteRange) -> Self {
+    pub fn with_range<T: ToString>(uri: T, range: ByteRange) -> Self {
         ExtXMap {
-            uri,
+            uri: uri.to_string(),
             range: Some(range),
         }
     }
 
     /// Returns the URI that identifies a resource that contains the media initialization section.
-    pub fn uri(&self) -> &QuotedString {
+    pub const fn uri(&self) -> &String {
         &self.uri
     }
 
     /// Returns the range of the media initialization section.
-    pub fn range(&self) -> Option<ByteRange> {
+    pub const fn range(&self) -> Option<ByteRange> {
         self.range
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V6
     }
 }
@@ -48,9 +53,9 @@ impl ExtXMap {
 impl fmt::Display for ExtXMap {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", Self::PREFIX)?;
-        write!(f, "URI={}", self.uri)?;
-        if let Some(ref x) = self.range {
-            write!(f, ",BYTERANGE=\"{}\"", x)?;
+        write!(f, "URI={}", quote(&self.uri))?;
+        if let Some(value) = &self.range {
+            write!(f, ",BYTERANGE={}", quote(value))?;
         }
         Ok(())
     }
@@ -58,19 +63,18 @@ impl fmt::Display for ExtXMap {
 
 impl FromStr for ExtXMap {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
 
         let mut uri = None;
         let mut range = None;
-        let attrs = AttributePairs::parse(s.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "URI" => uri = Some(track!(value.parse())?),
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "URI" => uri = Some(unquote(value)),
                 "BYTERANGE" => {
-                    let s: QuotedString = track!(value.parse())?;
-                    range = Some(track!(s.parse())?);
+                    range = Some((unquote(value).parse())?);
                 }
                 _ => {
                     // [6.3.1. General Client Responsibilities]
@@ -79,7 +83,7 @@ impl FromStr for ExtXMap {
             }
         }
 
-        let uri = track_assert_some!(uri, ErrorKind::InvalidInput);
+        let uri = uri.ok_or(Error::missing_value("EXT-X-URI"))?;
         Ok(ExtXMap { uri, range })
     }
 }
@@ -90,21 +94,16 @@ mod test {
 
     #[test]
     fn ext_x_map() {
-        let tag = ExtXMap::new(QuotedString::new("foo").unwrap());
+        let tag = ExtXMap::new("foo");
         let text = r#"#EXT-X-MAP:URI="foo""#;
         assert_eq!(text.parse().ok(), Some(tag.clone()));
         assert_eq!(tag.to_string(), text);
         assert_eq!(tag.requires_version(), ProtocolVersion::V6);
 
-        let tag = ExtXMap::with_range(
-            QuotedString::new("foo").unwrap(),
-            ByteRange {
-                length: 9,
-                start: Some(2),
-            },
-        );
+        let tag = ExtXMap::with_range("foo", ByteRange::new(9, Some(2)));
         let text = r#"#EXT-X-MAP:URI="foo",BYTERANGE="9@2""#;
-        track_try_unwrap!(ExtXMap::from_str(text));
+        ExtXMap::from_str(text).unwrap();
+
         assert_eq!(text.parse().ok(), Some(tag.clone()));
         assert_eq!(tag.to_string(), text);
         assert_eq!(tag.requires_version(), ProtocolVersion::V6);

src/tags/media_segment/program_date_time.rs

@@ -1,49 +1,53 @@
-use crate::types::{ProtocolVersion, SingleLineString};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use chrono::{DateTime, FixedOffset};
+
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.2.6. EXT-X-PROGRAM-DATE-TIME]
 ///
 /// [4.3.2.6. EXT-X-PROGRAM-DATE-TIME]: https://tools.ietf.org/html/rfc8216#section-4.3.2.6
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ExtXProgramDateTime {
-    date_time: SingleLineString,
-}
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct ExtXProgramDateTime(DateTime<FixedOffset>);
 
 impl ExtXProgramDateTime {
     pub(crate) const PREFIX: &'static str = "#EXT-X-PROGRAM-DATE-TIME:";
 
     /// Makes a new `ExtXProgramDateTime` tag.
-    pub fn new(date_time: SingleLineString) -> Self {
-        ExtXProgramDateTime { date_time }
+    pub fn new<T: Into<DateTime<FixedOffset>>>(date_time: T) -> Self {
+        Self(date_time.into())
     }
 
     /// Returns the date-time of the first sample of the associated media segment.
-    pub fn date_time(&self) -> &SingleLineString {
-        &self.date_time
+    pub const fn date_time(&self) -> &DateTime<FixedOffset> {
+        &self.0
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
 
 impl fmt::Display for ExtXProgramDateTime {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}{}", Self::PREFIX, self.date_time)
+        let date_time = self.0.to_rfc3339();
+        write!(f, "{}{}", Self::PREFIX, date_time)
     }
 }
 
 impl FromStr for ExtXProgramDateTime {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
-        let suffix = s.split_at(Self::PREFIX.len()).1;
-        Ok(ExtXProgramDateTime {
-            date_time: track!(SingleLineString::new(suffix))?,
-        })
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
+
+        // TODO: parse with chrono
+        let date_time = DateTime::parse_from_rfc3339(input)?;
+        Ok(Self::new(date_time))
     }
 }
 
@@ -52,12 +56,34 @@ mod test {
     use super::*;
 
     #[test]
-    fn ext_x_program_date_time() {
-        let text = "#EXT-X-PROGRAM-DATE-TIME:2010-02-19T14:54:23.031+08:00";
-        assert!(text.parse::<ExtXProgramDateTime>().is_ok());
+    fn test_display() {
+        let date_time = "2010-02-19T14:54:23.031+08:00"
+            .parse::<DateTime<FixedOffset>>()
+            .unwrap();
 
-        let tag = text.parse::<ExtXProgramDateTime>().unwrap();
-        assert_eq!(tag.to_string(), text);
-        assert_eq!(tag.requires_version(), ProtocolVersion::V1);
+        let program_date_time = ExtXProgramDateTime::new(date_time);
+
+        assert_eq!(
+            program_date_time.to_string(),
+            "#EXT-X-PROGRAM-DATE-TIME:2010-02-19T14:54:23.031+08:00".to_string()
+        );
+    }
+
+    #[test]
+    fn test_parser() {
+        "#EXT-X-PROGRAM-DATE-TIME:2010-02-19T14:54:23.031+08:00"
+            .parse::<ExtXProgramDateTime>()
+            .unwrap();
+    }
+
+    #[test]
+    fn test_requires_version() {
+        let date_time = "2010-02-19T14:54:23.031+08:00"
+            .parse::<DateTime<FixedOffset>>()
+            .unwrap();
+
+        let program_date_time = ExtXProgramDateTime::new(date_time);
+
+        assert_eq!(program_date_time.requires_version(), ProtocolVersion::V1);
     }
 }

src/tags/mod.rs

@@ -2,12 +2,6 @@
 //!
 //! [4.3. Playlist Tags]: https://tools.ietf.org/html/rfc8216#section-4.3
 
-macro_rules! may_invalid {
-    ($expr:expr) => {
-        $expr.map_err(|e| track!(Error::from(ErrorKind::InvalidInput.cause(e))))
-    };
-}
-
 macro_rules! impl_from {
     ($to:ident, $from:ident) => {
         impl From<$from> for $to {

src/tags/shared/independent_segments.rs

@@ -1,8 +1,10 @@
-use crate::types::ProtocolVersion;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::types::ProtocolVersion;
+use crate::utils::tag;
+use crate::Error;
+
 /// [4.3.5.1. EXT-X-INDEPENDENT-SEGMENTS]
 ///
 /// [4.3.5.1. EXT-X-INDEPENDENT-SEGMENTS]: https://tools.ietf.org/html/rfc8216#section-4.3.5.1
@@ -12,7 +14,7 @@ impl ExtXIndependentSegments {
     pub(crate) const PREFIX: &'static str = "#EXT-X-INDEPENDENT-SEGMENTS";
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -25,8 +27,9 @@ impl fmt::Display for ExtXIndependentSegments {
 
 impl FromStr for ExtXIndependentSegments {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert_eq!(s, Self::PREFIX, ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        tag(input, Self::PREFIX)?;
         Ok(ExtXIndependentSegments)
     }
 }

src/tags/shared/start.rs

@@ -1,10 +1,11 @@
-use crate::attribute::AttributePairs;
-use crate::types::{ProtocolVersion, SignedDecimalFloatingPoint};
-use crate::utils::parse_yes_or_no;
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::str::FromStr;
 
+use crate::attribute::AttributePairs;
+use crate::types::{ProtocolVersion, SignedDecimalFloatingPoint};
+use crate::utils::{parse_yes_or_no, tag};
+use crate::Error;
+
 /// [4.3.5.2. EXT-X-START]
 ///
 /// [4.3.5.2. EXT-X-START]: https://tools.ietf.org/html/rfc8216#section-4.3.5.2
@@ -18,34 +19,46 @@ impl ExtXStart {
     pub(crate) const PREFIX: &'static str = "#EXT-X-START:";
 
     /// Makes a new `ExtXStart` tag.
-    pub fn new(time_offset: SignedDecimalFloatingPoint) -> Self {
+    /// # Panic
+    /// Panics if the time_offset value is infinite.
+    pub fn new(time_offset: f64) -> Self {
+        if time_offset.is_infinite() {
+            panic!("EXT-X-START: Floating point value must be finite!");
+        }
+
         ExtXStart {
-            time_offset,
+            time_offset: SignedDecimalFloatingPoint::new(time_offset).unwrap(),
             precise: false,
         }
     }
 
     /// Makes a new `ExtXStart` tag with the given `precise` flag.
-    pub fn with_precise(time_offset: SignedDecimalFloatingPoint, precise: bool) -> Self {
+    /// # Panic
+    /// Panics if the time_offset value is infinite.
+    pub fn with_precise(time_offset: f64, precise: bool) -> Self {
+        if time_offset.is_infinite() {
+            panic!("EXT-X-START: Floating point value must be finite!");
+        }
+
         ExtXStart {
-            time_offset,
+            time_offset: SignedDecimalFloatingPoint::new(time_offset).unwrap(),
             precise,
         }
     }
 
     /// Returns the time offset of the media segments in the playlist.
-    pub fn time_offset(&self) -> SignedDecimalFloatingPoint {
-        self.time_offset
+    pub const fn time_offset(&self) -> f64 {
+        self.time_offset.as_f64()
     }
 
     /// Returns whether clients should not render media stream whose presentation times are
     /// prior to the specified time offset.
-    pub fn precise(&self) -> bool {
+    pub const fn precise(&self) -> bool {
         self.precise
     }
 
     /// Returns the protocol compatibility version that this tag requires.
-    pub fn requires_version(&self) -> ProtocolVersion {
+    pub const fn requires_version(&self) -> ProtocolVersion {
         ProtocolVersion::V1
     }
 }
@@ -63,17 +76,17 @@ impl fmt::Display for ExtXStart {
 
 impl FromStr for ExtXStart {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(s.starts_with(Self::PREFIX), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let input = tag(input, Self::PREFIX)?;
 
         let mut time_offset = None;
         let mut precise = false;
-        let attrs = AttributePairs::parse(s.split_at(Self::PREFIX.len()).1);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "TIME-OFFSET" => time_offset = Some(track!(value.parse())?),
-                "PRECISE" => precise = track!(parse_yes_or_no(value))?,
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "TIME-OFFSET" => time_offset = Some((value.parse())?),
+                "PRECISE" => precise = (parse_yes_or_no(value))?,
                 _ => {
                     // [6.3.1. General Client Responsibilities]
                     // > ignore any attribute/value pair with an unrecognized AttributeName.
@@ -81,7 +94,8 @@ impl FromStr for ExtXStart {
             }
         }
 
-        let time_offset = track_assert_some!(time_offset, ErrorKind::InvalidInput);
+        let time_offset = time_offset.ok_or(Error::missing_value("EXT-X-TIME-OFFSET"))?;
+
         Ok(ExtXStart {
             time_offset,
             precise,
@@ -95,13 +109,13 @@ mod test {
 
     #[test]
     fn ext_x_start() {
-        let tag = ExtXStart::new(SignedDecimalFloatingPoint::new(-1.23).unwrap());
+        let tag = ExtXStart::new(-1.23);
         let text = "#EXT-X-START:TIME-OFFSET=-1.23";
         assert_eq!(text.parse().ok(), Some(tag));
         assert_eq!(tag.to_string(), text);
         assert_eq!(tag.requires_version(), ProtocolVersion::V1);
 
-        let tag = ExtXStart::with_precise(SignedDecimalFloatingPoint::new(1.23).unwrap(), true);
+        let tag = ExtXStart::with_precise(1.23, true);
         let text = "#EXT-X-START:TIME-OFFSET=1.23,PRECISE=YES";
         assert_eq!(text.parse().ok(), Some(tag));
         assert_eq!(tag.to_string(), text);

src/types/byte_range.rs

@@ -1,18 +1,31 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
-use trackable::error::ErrorKindExt;
+use std::str::FromStr;
+
+use getset::{Getters, MutGetters, Setters};
+
+use crate::Error;
 
 /// Byte range.
 ///
 /// See: [4.3.2.2. EXT-X-BYTERANGE]
 ///
 /// [4.3.2.2. EXT-X-BYTERANGE]: https://tools.ietf.org/html/rfc8216#section-4.3.2.2
-#[allow(missing_docs)]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Getters, Setters, MutGetters, Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[get = "pub"]
+#[set = "pub"]
+#[get_mut = "pub"]
 pub struct ByteRange {
-    pub length: usize,
-    pub start: Option<usize>,
+    /// The length of the range.
+    length: usize,
+    /// The start of the range.
+    start: Option<usize>,
+}
+
+impl ByteRange {
+    /// Creates a new [ByteRange].
+    pub const fn new(length: usize, start: Option<usize>) -> Self {
+        Self { length, start }
+    }
 }
 
 impl fmt::Display for ByteRange {
@@ -27,20 +40,23 @@ impl fmt::Display for ByteRange {
 
 impl FromStr for ByteRange {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        let mut tokens = s.splitn(2, '@');
-        let length = tokens.next().expect("Never fails");
-        let start = if let Some(start) = tokens.next() {
-            Some(track!(start
-                .parse()
-                .map_err(|e| ErrorKind::InvalidInput.cause(e)))?)
-        } else {
-            None
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let tokens = s.splitn(2, '@').collect::<Vec<_>>();
+        if tokens.is_empty() {
+            return Err(Error::invalid_input());
+        }
+
+        let length = tokens[0].parse()?;
+
+        let start = {
+            let mut result = None;
+            if tokens.len() == 2 {
+                result = Some(tokens[1].parse()?);
+            }
+            result
         };
-        Ok(ByteRange {
-            length: track!(length.parse().map_err(|e| ErrorKind::InvalidInput.cause(e)))?,
-            start,
-        })
+        Ok(ByteRange::new(length, start))
     }
 }
 

src/types/closed_captions.rs

@@ -1,7 +1,8 @@
-use crate::types::QuotedString;
-use crate::{Error, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
+
+use crate::utils::{quote, unquote};
+use crate::{Error, Result};
 
 /// The identifier of a closed captions group or its absence.
 ///
@@ -11,14 +12,14 @@ use std::str::{self, FromStr};
 #[allow(missing_docs)]
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum ClosedCaptions {
-    GroupId(QuotedString),
+    GroupId(String),
     None,
 }
 
 impl fmt::Display for ClosedCaptions {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            ClosedCaptions::GroupId(ref x) => x.fmt(f),
+        match &self {
+            ClosedCaptions::GroupId(value) => write!(f, "{}", quote(value)),
             ClosedCaptions::None => "NONE".fmt(f),
         }
     }
@@ -30,7 +31,7 @@ impl FromStr for ClosedCaptions {
         if s == "NONE" {
             Ok(ClosedCaptions::None)
         } else {
-            Ok(ClosedCaptions::GroupId(track!(s.parse())?))
+            Ok(ClosedCaptions::GroupId(unquote(s)))
         }
     }
 }
@@ -44,7 +45,7 @@ mod tests {
         let closed_captions = ClosedCaptions::None;
         assert_eq!(closed_captions.to_string(), "NONE".to_string());
 
-        let closed_captions = ClosedCaptions::GroupId(QuotedString::new("value").unwrap());
+        let closed_captions = ClosedCaptions::GroupId("value".into());
         assert_eq!(closed_captions.to_string(), "\"value\"".to_string());
     }
 
@@ -53,7 +54,7 @@ mod tests {
         let closed_captions = ClosedCaptions::None;
         assert_eq!(closed_captions, "NONE".parse::<ClosedCaptions>().unwrap());
 
-        let closed_captions = ClosedCaptions::GroupId(QuotedString::new("value").unwrap());
+        let closed_captions = ClosedCaptions::GroupId("value".into());
         assert_eq!(
             closed_captions,
             "\"value\"".parse::<ClosedCaptions>().unwrap()

src/types/decimal_floating_point.rs

@@ -1,8 +1,8 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
 use std::time::Duration;
-use trackable::error::ErrorKindExt;
+
+use crate::Error;
 
 /// Non-negative decimal floating-point number.
 ///
@@ -10,7 +10,7 @@ use trackable::error::ErrorKindExt;
 ///
 /// [4.2. Attribute Lists]: https://tools.ietf.org/html/rfc8216#section-4.2
 #[derive(Debug, Clone, Copy, PartialEq, PartialOrd)]
-pub struct DecimalFloatingPoint(f64);
+pub(crate) struct DecimalFloatingPoint(f64);
 
 impl DecimalFloatingPoint {
     /// Makes a new `DecimalFloatingPoint` instance.
@@ -19,14 +19,15 @@ impl DecimalFloatingPoint {
     ///
     /// The given value must have a positive sign and be finite,
     /// otherwise this function will return an error that has the kind `ErrorKind::InvalidInput`.
-    pub fn new(n: f64) -> Result<Self> {
-        track_assert!(n.is_sign_positive(), ErrorKind::InvalidInput);
-        track_assert!(n.is_finite(), ErrorKind::InvalidInput);
+    pub fn new(n: f64) -> crate::Result<Self> {
+        if !n.is_sign_positive() || !n.is_finite() {
+            return Err(Error::invalid_input());
+        }
         Ok(DecimalFloatingPoint(n))
     }
 
     /// Converts `DecimalFloatingPoint` to `f64`.
-    pub fn as_f64(self) -> f64 {
+    pub const fn as_f64(self) -> f64 {
         self.0
     }
 
@@ -59,13 +60,13 @@ impl fmt::Display for DecimalFloatingPoint {
 
 impl FromStr for DecimalFloatingPoint {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(
-            s.chars().all(|c| c.is_digit(10) || c == '.'),
-            ErrorKind::InvalidInput
-        );
-        let n = track!(s.parse().map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
-        Ok(DecimalFloatingPoint(n))
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        if !input.chars().all(|c| c.is_digit(10) || c == '.') {
+            return Err(Error::invalid_input());
+        }
+        let n = input.parse()?;
+        DecimalFloatingPoint::new(n)
     }
 }
 

src/types/decimal_resolution.rs

@@ -1,7 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
-use trackable::error::ErrorKindExt;
+use std::str::FromStr;
+
+use crate::Error;
 
 /// Decimal resolution.
 ///
@@ -9,12 +9,38 @@ use trackable::error::ErrorKindExt;
 ///
 /// [4.2. Attribute Lists]: https://tools.ietf.org/html/rfc8216#section-4.2
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct DecimalResolution {
+pub(crate) struct DecimalResolution {
+    width: usize,
+    height: usize,
+}
+
+impl DecimalResolution {
+    /// Creates a new DecimalResolution.
+    pub const fn new(width: usize, height: usize) -> Self {
+        Self { width, height }
+    }
+
     /// Horizontal pixel dimension.
-    pub width: usize,
+    pub const fn width(&self) -> usize {
+        self.width
+    }
+
+    /// Sets Horizontal pixel dimension.
+    pub fn set_width(&mut self, value: usize) -> &mut Self {
+        self.width = value;
+        self
+    }
 
     /// Vertical pixel dimension.
-    pub height: usize,
+    pub const fn height(&self) -> usize {
+        self.height
+    }
+
+    /// Sets Vertical pixel dimension.
+    pub fn set_height(&mut self, value: usize) -> &mut Self {
+        self.height = value;
+        self
+    }
 }
 
 impl fmt::Display for DecimalResolution {
@@ -25,13 +51,23 @@ impl fmt::Display for DecimalResolution {
 
 impl FromStr for DecimalResolution {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        let mut tokens = s.splitn(2, 'x');
-        let width = tokens.next().expect("Never fails");
-        let height = track_assert_some!(tokens.next(), ErrorKind::InvalidInput);
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        let tokens = input.splitn(2, 'x').collect::<Vec<_>>();
+
+        if tokens.len() != 2 {
+            return Err(Error::custom(format!(
+                "InvalidInput: Expected input format: [width]x[height] (ex. 1920x1080), got {:?}",
+                input,
+            )));
+        }
+
+        let width = tokens[0];
+        let height = tokens[1];
+
         Ok(DecimalResolution {
-            width: track!(width.parse().map_err(|e| ErrorKind::InvalidInput.cause(e)))?,
-            height: track!(height.parse().map_err(|e| ErrorKind::InvalidInput.cause(e)))?,
+            width: width.parse()?,
+            height: height.parse()?,
         })
     }
 }
@@ -42,37 +78,44 @@ mod tests {
 
     #[test]
     fn test_display() {
-        let decimal_resolution = DecimalResolution {
-            width: 1920,
-            height: 1080,
-        };
-        assert_eq!(decimal_resolution.to_string(), "1920x1080".to_string());
+        assert_eq!(
+            DecimalResolution::new(1920, 1080).to_string(),
+            "1920x1080".to_string()
+        );
 
-        let decimal_resolution = DecimalResolution {
-            width: 1280,
-            height: 720,
-        };
-        assert_eq!(decimal_resolution.to_string(), "1280x720".to_string());
+        assert_eq!(
+            DecimalResolution::new(1280, 720).to_string(),
+            "1280x720".to_string()
+        );
     }
 
     #[test]
     fn test_parse() {
-        let decimal_resolution = DecimalResolution {
-            width: 1920,
-            height: 1080,
-        };
         assert_eq!(
-            decimal_resolution,
+            DecimalResolution::new(1920, 1080),
             "1920x1080".parse::<DecimalResolution>().unwrap()
         );
 
-        let decimal_resolution = DecimalResolution {
-            width: 1280,
-            height: 720,
-        };
         assert_eq!(
-            decimal_resolution,
+            DecimalResolution::new(1280, 720),
             "1280x720".parse::<DecimalResolution>().unwrap()
         );
+
+        assert!("1280".parse::<DecimalResolution>().is_err());
+    }
+
+    #[test]
+    fn test_width() {
+        assert_eq!(DecimalResolution::new(1920, 1080).width(), 1920);
+        assert_eq!(DecimalResolution::new(1920, 1080).set_width(12).width(), 12);
+    }
+
+    #[test]
+    fn test_height() {
+        assert_eq!(DecimalResolution::new(1920, 1080).height(), 1080);
+        assert_eq!(
+            DecimalResolution::new(1920, 1080).set_height(12).height(),
+            12
+        );
     }
 }

src/types/decryption_key.rs

@@ -1,27 +1,316 @@
-use crate::attribute::AttributePairs;
-use crate::types::{EncryptionMethod, InitializationVector, ProtocolVersion, QuotedString};
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
 
-/// Decryption key.
-///
-/// See: [4.3.2.4. EXT-X-KEY]
-///
-/// [4.3.2.4. EXT-X-KEY]: https://tools.ietf.org/html/rfc8216#section-4.3.2.4
-#[allow(missing_docs)]
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+use derive_builder::Builder;
+use url::Url;
+
+use crate::attribute::AttributePairs;
+use crate::types::{EncryptionMethod, InitializationVector, ProtocolVersion};
+use crate::utils::{quote, unquote};
+use crate::Error;
+
+#[derive(Builder, Debug, Clone, PartialEq, Eq, Hash)]
+#[builder(setter(into))]
 pub struct DecryptionKey {
-    pub method: EncryptionMethod,
-    pub uri: QuotedString,
-    pub iv: Option<InitializationVector>,
-    pub key_format: Option<QuotedString>,
-    pub key_format_versions: Option<QuotedString>,
+    pub(crate) method: EncryptionMethod,
+    #[builder(setter(into, strip_option), default)]
+    pub(crate) uri: Option<Url>,
+    #[builder(setter(into, strip_option), default)]
+    pub(crate) iv: Option<InitializationVector>,
+    #[builder(setter(into, strip_option), default)]
+    pub(crate) key_format: Option<String>,
+    #[builder(setter(into, strip_option), default)]
+    pub(crate) key_format_versions: Option<String>,
 }
 
 impl DecryptionKey {
-    pub(crate) fn requires_version(&self) -> ProtocolVersion {
-        if self.key_format.is_some() | self.key_format_versions.is_some() {
+    /// Makes a new `DecryptionKey`.
+    /// # Example
+    /// ```
+    /// use url::Url;
+    ///
+    /// use hls_m3u8::types::{EncryptionMethod, DecryptionKey};
+    ///
+    /// let key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "METHOD=AES-128,URI=\"https://www.example.com/\""
+    /// );
+    /// ```
+    pub const fn new(method: EncryptionMethod, uri: Url) -> Self {
+        Self {
+            method,
+            uri: Some(uri),
+            iv: None,
+            key_format: None,
+            key_format_versions: None,
+        }
+    }
+
+    /// Returns the [EncryptionMethod].
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// assert_eq!(
+    ///     key.method(),
+    ///     EncryptionMethod::Aes128
+    /// );
+    /// ```
+    pub const fn method(&self) -> EncryptionMethod {
+        self.method
+    }
+
+    /// Returns a Builder to build a `DecryptionKey`.
+    pub fn builder() -> DecryptionKeyBuilder {
+        DecryptionKeyBuilder::default()
+    }
+
+    /// Sets the [EncryptionMethod].
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_method(EncryptionMethod::SampleAes);
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "METHOD=SAMPLE-AES,URI=\"https://www.example.com/\"".to_string()
+    /// );
+    /// ```
+    pub fn set_method(&mut self, value: EncryptionMethod) {
+        self.method = value;
+    }
+
+    /// Returns an `URI` that specifies how to obtain the key.
+    ///
+    /// This attribute is required, if the [EncryptionMethod] is not None.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// assert_eq!(
+    ///     key.uri(),
+    ///     &Some("https://www.example.com".parse().unwrap())
+    /// );
+    /// ```
+    pub const fn uri(&self) -> &Option<Url> {
+        &self.uri
+    }
+
+    /// Sets the `URI` attribute.
+    ///
+    /// This attribute is required, if the [EncryptionMethod] is not None.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_uri("http://www.google.com".parse().unwrap());
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "METHOD=AES-128,URI=\"http://www.google.com/\"".to_string()
+    /// );
+    /// ```
+    pub fn set_uri(&mut self, value: Url) {
+        self.uri = Some(value);
+    }
+
+    /// Returns the IV (Initialization Vector) attribute.
+    ///
+    /// This attribute is optional.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_iv([
+    ///    1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7
+    /// ]);
+    ///
+    /// assert_eq!(
+    ///     key.iv(),
+    ///     Some([1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7])
+    /// );
+    /// ```
+    pub fn iv(&self) -> Option<[u8; 16]> {
+        if let Some(iv) = &self.iv {
+            Some(iv.to_slice())
+        } else {
+            None
+        }
+    }
+
+    /// Sets the `IV` attribute.
+    ///
+    /// This attribute is optional.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_iv([
+    ///    1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7
+    /// ]);
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "METHOD=AES-128,URI=\"https://www.example.com/\",IV=0x01020304050607080901020304050607".to_string()
+    /// );
+    /// ```
+    pub fn set_iv<T>(&mut self, value: T)
+    where
+        T: Into<[u8; 16]>,
+    {
+        self.iv = Some(InitializationVector(value.into()));
+    }
+
+    /// Returns a string that specifies how the key is
+    /// represented in the resource identified by the URI.
+    ///
+    //// This attribute is optional.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_key_format("key_format_attribute");
+    ///
+    /// assert_eq!(
+    ///     key.key_format(),
+    ///     &Some("key_format_attribute".to_string())
+    /// );
+    /// ```
+    pub const fn key_format(&self) -> &Option<String> {
+        &self.key_format
+    }
+
+    /// Sets the `KEYFORMAT` attribute.
+    ///
+    /// This attribute is optional.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_key_format("key_format_attribute");
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "METHOD=AES-128,URI=\"https://www.example.com/\",KEYFORMAT=\"key_format_attribute\"".to_string()
+    /// );
+    /// ```
+    pub fn set_key_format<T: ToString>(&mut self, value: T) {
+        self.key_format = Some(value.to_string());
+    }
+
+    /// Returns a string containing one or more positive
+    /// integers separated by the "/" character (for example, "1", "1/2",
+    /// or "1/2/5").  If more than one version of a particular `KEYFORMAT`
+    /// is defined, this attribute can be used to indicate which
+    /// version(s) this instance complies with.
+    ///
+    /// This attribute is optional.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_key_format_versions("1/2/3/4/5");
+    ///
+    /// assert_eq!(
+    ///     key.key_format_versions(),
+    ///     &Some("1/2/3/4/5".to_string())
+    /// );
+    /// ```
+    pub const fn key_format_versions(&self) -> &Option<String> {
+        &self.key_format_versions
+    }
+
+    /// Sets the `KEYFORMATVERSIONS` attribute.
+    ///
+    /// This attribute is optional.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{DecryptionKey, EncryptionMethod};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// key.set_key_format_versions("1/2/3/4/5");
+    ///
+    /// assert_eq!(
+    ///     key.to_string(),
+    ///     "METHOD=AES-128,URI=\"https://www.example.com/\",KEYFORMATVERSIONS=\"1/2/3/4/5\"".to_string()
+    /// );
+    /// ```
+    pub fn set_key_format_versions<T: ToString>(&mut self, value: T) {
+        self.key_format_versions = Some(value.to_string());
+    }
+
+    /// Returns the protocol compatibility version that this tag requires.
+    /// # Example
+    /// ```
+    /// use hls_m3u8::types::{EncryptionMethod, ProtocolVersion, DecryptionKey};
+    ///
+    /// let mut key = DecryptionKey::new(
+    ///     EncryptionMethod::Aes128,
+    ///     "https://www.example.com".parse().unwrap()
+    /// );
+    ///
+    /// assert_eq!(
+    ///     key.requires_version(),
+    ///     ProtocolVersion::V1
+    /// );
+    /// ```
+    pub fn requires_version(&self) -> ProtocolVersion {
+        if self.key_format.is_some() || self.key_format_versions.is_some() {
             ProtocolVersion::V5
         } else if self.iv.is_some() {
             ProtocolVersion::V2
@@ -31,48 +320,35 @@ impl DecryptionKey {
     }
 }
 
-impl fmt::Display for DecryptionKey {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "METHOD={}", self.method)?;
-        write!(f, ",URI={}", self.uri)?;
-        if let Some(ref x) = self.iv {
-            write!(f, ",IV={}", x)?;
-        }
-        if let Some(ref x) = self.key_format {
-            write!(f, ",KEYFORMAT={}", x)?;
-        }
-        if let Some(ref x) = self.key_format_versions {
-            write!(f, ",KEYFORMATVERSIONS={}", x)?;
-        }
-        Ok(())
-    }
-}
-
 impl FromStr for DecryptionKey {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
         let mut method = None;
         let mut uri = None;
         let mut iv = None;
         let mut key_format = None;
         let mut key_format_versions = None;
-        let attrs = AttributePairs::parse(s);
-        for attr in attrs {
-            let (key, value) = track!(attr)?;
-            match key {
-                "METHOD" => method = Some(track!(value.parse())?),
-                "URI" => uri = Some(track!(value.parse())?),
-                "IV" => iv = Some(track!(value.parse())?),
-                "KEYFORMAT" => key_format = Some(track!(value.parse())?),
-                "KEYFORMATVERSIONS" => key_format_versions = Some(track!(value.parse())?),
+
+        for (key, value) in input.parse::<AttributePairs>()? {
+            match key.as_str() {
+                "METHOD" => method = Some((value.parse())?),
+                "URI" => uri = Some(unquote(value).parse()?),
+                "IV" => iv = Some((value.parse())?),
+                "KEYFORMAT" => key_format = Some(unquote(value)),
+                "KEYFORMATVERSIONS" => key_format_versions = Some(unquote(value)),
                 _ => {
                     // [6.3.1. General Client Responsibilities]
                     // > ignore any attribute/value pair with an unrecognized AttributeName.
                 }
             }
         }
-        let method = track_assert_some!(method, ErrorKind::InvalidInput);
-        let uri = track_assert_some!(uri, ErrorKind::InvalidInput);
+
+        let method = method.ok_or(Error::missing_value("METHOD"))?;
+        if method != EncryptionMethod::None && uri.is_none() {
+            return Err(Error::missing_value("URI"));
+        }
+
         Ok(DecryptionKey {
             method,
             uri,
@@ -82,3 +358,108 @@ impl FromStr for DecryptionKey {
         })
     }
 }
+
+impl fmt::Display for DecryptionKey {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "METHOD={}", self.method)?;
+
+        if self.method == EncryptionMethod::None {
+            return Ok(());
+        }
+        if let Some(uri) = &self.uri {
+            write!(f, ",URI={}", quote(uri))?;
+        }
+        if let Some(value) = &self.iv {
+            write!(f, ",IV={}", value)?;
+        }
+        if let Some(value) = &self.key_format {
+            write!(f, ",KEYFORMAT={}", quote(value))?;
+        }
+        if let Some(value) = &self.key_format_versions {
+            write!(f, ",KEYFORMATVERSIONS={}", quote(value))?;
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::types::EncryptionMethod;
+
+    #[test]
+    fn test_requires_version() {
+        let key = DecryptionKey::builder()
+            .method(EncryptionMethod::Aes128)
+            .uri("https://www.example.com".parse::<Url>().unwrap())
+            .iv([
+                16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+            ])
+            .build()
+            .unwrap();
+    }
+
+    #[test]
+    fn test_display() {
+        let mut key = DecryptionKey::new(
+            EncryptionMethod::Aes128,
+            "https://www.example.com/hls-key/key.bin".parse().unwrap(),
+        );
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
+
+        assert_eq!(
+            key.to_string(),
+            "METHOD=AES-128,\
+             URI=\"https://www.example.com/hls-key/key.bin\",\
+             IV=0x10ef8f758ca555115584bb5b3c687f52"
+                .to_string()
+        );
+    }
+
+    #[test]
+    fn test_parser() {
+        assert_eq!(
+            r#"METHOD=AES-128,URI="https://priv.example.com/key.php?r=52""#
+                .parse::<DecryptionKey>()
+                .unwrap(),
+            DecryptionKey::new(
+                EncryptionMethod::Aes128,
+                "https://priv.example.com/key.php?r=52".parse().unwrap()
+            )
+        );
+
+        let mut key = DecryptionKey::new(
+            EncryptionMethod::Aes128,
+            "https://www.example.com/hls-key/key.bin".parse().unwrap(),
+        );
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
+
+        assert_eq!(
+            "METHOD=AES-128,\
+             URI=\"https://www.example.com/hls-key/key.bin\",\
+             IV=0X10ef8f758ca555115584bb5b3c687f52"
+                .parse::<DecryptionKey>()
+                .unwrap(),
+            key
+        );
+
+        let mut key = DecryptionKey::new(
+            EncryptionMethod::Aes128,
+            "http://www.example.com".parse().unwrap(),
+        );
+        key.set_iv([
+            16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+        ]);
+        key.set_key_format("baz");
+
+        assert_eq!(
+            r#"METHOD=AES-128,URI="http://www.example.com",IV=0x10ef8f758ca555115584bb5b3c687f52,KEYFORMAT="baz""#
+            .parse::<DecryptionKey>().unwrap(),
+            key
+        )
+    }
+}

src/types/encryption_method.rs

@@ -1,6 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
+
+use crate::Error;
 
 /// Encryption method.
 ///
@@ -10,30 +11,65 @@ use std::str::{self, FromStr};
 #[allow(missing_docs)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum EncryptionMethod {
+    /// `None` means that [MediaSegment]s are not encrypted.
+    ///
+    /// [MediaSegment]: crate::MediaSegment
+    None,
+    /// `Aes128` signals that the [MediaSegment]s are completely encrypted
+    /// using the Advanced Encryption Standard ([AES_128]) with a 128-bit
+    /// key, Cipher Block Chaining (CBC), and
+    /// [Public-Key Cryptography Standards #7 (PKCS7)] padding.
+    /// CBC is restarted on each segment boundary, using either the
+    /// Initialization Vector (IV) attribute value or the Media Sequence
+    /// Number as the IV.
+    ///
+    /// [MediaSegment]: crate::MediaSegment
+    /// [AES_128]: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197.pdf
+    /// [Public-Key Cryptography Standards #7 (PKCS7)]: https://tools.ietf.org/html/rfc5652
     Aes128,
+    /// `SampleAes` means that the [MediaSegment]s
+    /// contain media samples, such as audio or video, that are encrypted
+    /// using the Advanced Encryption Standard ([AES_128]). How these media
+    /// streams are encrypted and encapsulated in a segment depends on the
+    /// media encoding and the media format of the segment. fMP4 Media
+    /// Segments are encrypted using the 'cbcs' scheme of
+    /// [Common Encryption].  Encryption of other Media Segment
+    /// formats containing [H.264], [AAC], [AC-3],
+    /// and Enhanced [AC-3] media streams is described in the HTTP
+    /// Live Streaming (HLS) [SampleEncryption specification].
+    ///
+    /// [MediaSegment]: crate::MediaSegment
+    /// [AES_128]: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197.pdf
+    /// [Common Encryption]: https://tools.ietf.org/html/rfc8216#ref-COMMON_ENC
+    /// [H.264]: https://tools.ietf.org/html/rfc8216#ref-H_264
+    /// [AAC]: https://tools.ietf.org/html/rfc8216#ref-ISO_14496
+    /// [AC-3]: https://tools.ietf.org/html/rfc8216#ref-AC_3
+    /// [SampleEncryption specification]: https://tools.ietf.org/html/rfc8216#ref-SampleEnc
     SampleAes,
 }
 
 impl fmt::Display for EncryptionMethod {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
+        match &self {
             EncryptionMethod::Aes128 => "AES-128".fmt(f),
             EncryptionMethod::SampleAes => "SAMPLE-AES".fmt(f),
+            EncryptionMethod::None => "NONE".fmt(f),
         }
     }
 }
 
 impl FromStr for EncryptionMethod {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        match s {
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        match input {
             "AES-128" => Ok(EncryptionMethod::Aes128),
             "SAMPLE-AES" => Ok(EncryptionMethod::SampleAes),
-            _ => track_panic!(
-                ErrorKind::InvalidInput,
+            "NONE" => Ok(EncryptionMethod::None),
+            _ => Err(Error::custom(format!(
                 "Unknown encryption method: {:?}",
-                s
-            ),
+                input
+            ))),
         }
     }
 }
@@ -44,25 +80,29 @@ mod tests {
 
     #[test]
     fn test_display() {
-        let encryption_method = EncryptionMethod::Aes128;
-        assert_eq!(encryption_method.to_string(), "AES-128".to_string());
-
-        let encryption_method = EncryptionMethod::SampleAes;
-        assert_eq!(encryption_method.to_string(), "SAMPLE-AES".to_string());
+        assert_eq!(EncryptionMethod::Aes128.to_string(), "AES-128".to_string());
+        assert_eq!(
+            EncryptionMethod::SampleAes.to_string(),
+            "SAMPLE-AES".to_string()
+        );
+        assert_eq!(EncryptionMethod::None.to_string(), "NONE".to_string());
     }
 
     #[test]
     fn test_parse() {
-        let encryption_method = EncryptionMethod::Aes128;
         assert_eq!(
-            encryption_method,
+            EncryptionMethod::Aes128,
             "AES-128".parse::<EncryptionMethod>().unwrap()
         );
 
-        let encryption_method = EncryptionMethod::SampleAes;
         assert_eq!(
-            encryption_method,
+            EncryptionMethod::SampleAes,
             "SAMPLE-AES".parse::<EncryptionMethod>().unwrap()
         );
+
+        assert_eq!(
+            EncryptionMethod::None,
+            "NONE".parse::<EncryptionMethod>().unwrap()
+        );
     }
 }

src/types/hdcp_level.rs

@@ -1,6 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
+
+use crate::Error;
 
 /// HDCP level.
 ///
@@ -16,7 +17,7 @@ pub enum HdcpLevel {
 
 impl fmt::Display for HdcpLevel {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
+        match &self {
             HdcpLevel::Type0 => "TYPE-0".fmt(f),
             HdcpLevel::None => "NONE".fmt(f),
         }
@@ -25,11 +26,12 @@ impl fmt::Display for HdcpLevel {
 
 impl FromStr for HdcpLevel {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        match s {
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        match input {
             "TYPE-0" => Ok(HdcpLevel::Type0),
             "NONE" => Ok(HdcpLevel::None),
-            _ => track_panic!(ErrorKind::InvalidInput, "Unknown HDCP level: {:?}", s),
+            _ => Err(Error::custom(format!("Unknown HDCP level: {:?}", input))),
         }
     }
 }

src/types/hexadecimal_sequence.rs

@@ -1,68 +0,0 @@
-use crate::{Error, ErrorKind, Result};
-use std::fmt;
-use std::ops::Deref;
-use std::str::{self, FromStr};
-use trackable::error::ErrorKindExt;
-
-/// Hexadecimal sequence.
-///
-/// See: [4.2. Attribute Lists]
-///
-/// [4.2. Attribute Lists]: https://tools.ietf.org/html/rfc8216#section-4.2
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct HexadecimalSequence(Vec<u8>);
-
-impl HexadecimalSequence {
-    /// Makes a new `HexadecimalSequence` instance.
-    pub fn new<T: Into<Vec<u8>>>(v: T) -> Self {
-        HexadecimalSequence(v.into())
-    }
-
-    /// Converts into the underlying byte sequence.
-    pub fn into_bytes(self) -> Vec<u8> {
-        self.0
-    }
-}
-
-impl Deref for HexadecimalSequence {
-    type Target = [u8];
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl AsRef<[u8]> for HexadecimalSequence {
-    fn as_ref(&self) -> &[u8] {
-        &self.0
-    }
-}
-
-impl fmt::Display for HexadecimalSequence {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "0x")?;
-        for b in &self.0 {
-            write!(f, "{:02x}", b)?;
-        }
-        Ok(())
-    }
-}
-
-impl FromStr for HexadecimalSequence {
-    type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(
-            s.starts_with("0x") || s.starts_with("0X"),
-            ErrorKind::InvalidInput
-        );
-        track_assert!(s.len() % 2 == 0, ErrorKind::InvalidInput);
-
-        let mut v = Vec::with_capacity(s.len() / 2 - 1);
-        for c in s.as_bytes().chunks(2).skip(1) {
-            let d = track!(str::from_utf8(c).map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
-            let b =
-                track!(u8::from_str_radix(d, 16).map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
-            v.push(b);
-        }
-        Ok(HexadecimalSequence(v))
-    }
-}

src/types/in_stream_id.rs

@@ -1,6 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
+
+use crate::Error;
 
 /// Identifier of a rendition within the segments in a media playlist.
 ///
@@ -87,8 +88,9 @@ impl fmt::Display for InStreamId {
 
 impl FromStr for InStreamId {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        Ok(match s {
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        Ok(match input {
             "CC1" => InStreamId::Cc1,
             "CC2" => InStreamId::Cc2,
             "CC3" => InStreamId::Cc3,
@@ -156,7 +158,7 @@ impl FromStr for InStreamId {
             "SERVICE61" => InStreamId::Service61,
             "SERVICE62" => InStreamId::Service62,
             "SERVICE63" => InStreamId::Service63,
-            _ => track_panic!(ErrorKind::InvalidInput, "Unknown instream id: {:?}", s),
+            _ => return Err(Error::custom(format!("Unknown instream id: {:?}", input))),
         })
     }
 }

src/types/initialization_vector.rs

@@ -1,8 +1,8 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
 use std::ops::Deref;
-use std::str::{self, FromStr};
-use trackable::error::ErrorKindExt;
+use std::str::FromStr;
+
+use crate::Error;
 
 /// Initialization vector.
 ///
@@ -12,6 +12,19 @@ use trackable::error::ErrorKindExt;
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct InitializationVector(pub [u8; 16]);
 
+impl InitializationVector {
+    /// Converts the initialization vector to a slice.
+    pub const fn to_slice(&self) -> [u8; 16] {
+        self.0
+    }
+}
+
+impl From<[u8; 16]> for InitializationVector {
+    fn from(value: [u8; 16]) -> Self {
+        Self(value)
+    }
+}
+
 impl Deref for InitializationVector {
     type Target = [u8];
     fn deref(&self) -> &Self::Target {
@@ -37,20 +50,22 @@ impl fmt::Display for InitializationVector {
 
 impl FromStr for InitializationVector {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(
-            s.starts_with("0x") || s.starts_with("0X"),
-            ErrorKind::InvalidInput
-        );
-        track_assert_eq!(s.len() - 2, 32, ErrorKind::InvalidInput);
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if !(s.starts_with("0x") || s.starts_with("0X")) {
+            return Err(Error::invalid_input());
+        }
+        if s.len() - 2 != 32 {
+            return Err(Error::invalid_input());
+        }
 
         let mut v = [0; 16];
         for (i, c) in s.as_bytes().chunks(2).skip(1).enumerate() {
-            let d = track!(str::from_utf8(c).map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
-            let b =
-                track!(u8::from_str_radix(d, 16).map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
+            let d = std::str::from_utf8(c).map_err(|e| Error::custom(e))?;
+            let b = u8::from_str_radix(d, 16).map_err(|e| Error::custom(e))?;
             v[i] = b;
         }
+
         Ok(InitializationVector(v))
     }
 }

src/types/media_type.rs

@@ -1,6 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
+
+use crate::Error;
 
 /// Media type.
 ///
@@ -18,7 +19,7 @@ pub enum MediaType {
 
 impl fmt::Display for MediaType {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
+        match &self {
             MediaType::Audio => "AUDIO".fmt(f),
             MediaType::Video => "VIDEO".fmt(f),
             MediaType::Subtitles => "SUBTITLES".fmt(f),
@@ -29,13 +30,16 @@ impl fmt::Display for MediaType {
 
 impl FromStr for MediaType {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        Ok(match s {
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        Ok(match input {
             "AUDIO" => MediaType::Audio,
             "VIDEO" => MediaType::Video,
             "SUBTITLES" => MediaType::Subtitles,
             "CLOSED-CAPTIONS" => MediaType::ClosedCaptions,
-            _ => track_panic!(ErrorKind::InvalidInput, "Unknown media type: {:?}", s),
+            _ => {
+                return Err(Error::invalid_input());
+            }
         })
     }
 }

src/types/mod.rs

@@ -6,31 +6,21 @@ mod decimal_resolution;
 mod decryption_key;
 mod encryption_method;
 mod hdcp_level;
-mod hexadecimal_sequence;
 mod in_stream_id;
 mod initialization_vector;
 mod media_type;
-mod playlist_type;
 mod protocol_version;
-mod quoted_string;
-mod session_data;
 mod signed_decimal_floating_point;
-mod single_line_string;
 
 pub use byte_range::*;
 pub use closed_captions::*;
-pub use decimal_floating_point::*;
-pub use decimal_resolution::*;
+pub(crate) use decimal_floating_point::*;
+pub(crate) use decimal_resolution::*;
 pub use decryption_key::*;
 pub use encryption_method::*;
 pub use hdcp_level::*;
-pub use hexadecimal_sequence::*;
 pub use in_stream_id::*;
 pub use initialization_vector::*;
 pub use media_type::*;
-pub use playlist_type::*;
 pub use protocol_version::*;
-pub use quoted_string::*;
-pub use session_data::*;
-pub use signed_decimal_floating_point::*;
-pub use single_line_string::*;
+pub(crate) use signed_decimal_floating_point::*;

src/types/playlist_type.rs

@@ -1,35 +0,0 @@
-use crate::{Error, ErrorKind, Result};
-use std::fmt;
-use std::str::{self, FromStr};
-
-/// Playlist type.
-///
-/// See: [4.3.3.5. EXT-X-PLAYLIST-TYPE]
-///
-/// [4.3.3.5. EXT-X-PLAYLIST-TYPE]: https://tools.ietf.org/html/rfc8216#section-4.3.3.5
-#[allow(missing_docs)]
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum PlaylistType {
-    Event,
-    Vod,
-}
-
-impl fmt::Display for PlaylistType {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            PlaylistType::Event => write!(f, "EVENT"),
-            PlaylistType::Vod => write!(f, "VOD"),
-        }
-    }
-}
-
-impl FromStr for PlaylistType {
-    type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        match s {
-            "EVENT" => Ok(PlaylistType::Event),
-            "VOD" => Ok(PlaylistType::Vod),
-            _ => track_panic!(ErrorKind::InvalidInput, "Unknown playlist type: {:?}", s),
-        }
-    }
-}

src/types/protocol_version.rs

@@ -1,6 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
+use std::str::FromStr;
+
+use crate::Error;
 
 /// [7. Protocol Version Compatibility]
 ///
@@ -16,32 +17,46 @@ pub enum ProtocolVersion {
     V6,
     V7,
 }
+
+impl ProtocolVersion {
+    /// Returns the newest ProtocolVersion, that is supported by this library.
+    pub const fn latest() -> Self {
+        Self::V7
+    }
+}
+
 impl fmt::Display for ProtocolVersion {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let n = match *self {
-            ProtocolVersion::V1 => 1,
-            ProtocolVersion::V2 => 2,
-            ProtocolVersion::V3 => 3,
-            ProtocolVersion::V4 => 4,
-            ProtocolVersion::V5 => 5,
-            ProtocolVersion::V6 => 6,
-            ProtocolVersion::V7 => 7,
+        let n = {
+            match &self {
+                ProtocolVersion::V1 => 1,
+                ProtocolVersion::V2 => 2,
+                ProtocolVersion::V3 => 3,
+                ProtocolVersion::V4 => 4,
+                ProtocolVersion::V5 => 5,
+                ProtocolVersion::V6 => 6,
+                ProtocolVersion::V7 => 7,
+            }
         };
         write!(f, "{}", n)
     }
 }
+
 impl FromStr for ProtocolVersion {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        Ok(match s {
-            "1" => ProtocolVersion::V1,
-            "2" => ProtocolVersion::V2,
-            "3" => ProtocolVersion::V3,
-            "4" => ProtocolVersion::V4,
-            "5" => ProtocolVersion::V5,
-            "6" => ProtocolVersion::V6,
-            "7" => ProtocolVersion::V7,
-            _ => track_panic!(ErrorKind::InvalidInput, "Unknown protocol version: {:?}", s),
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        Ok({
+            match input {
+                "1" => ProtocolVersion::V1,
+                "2" => ProtocolVersion::V2,
+                "3" => ProtocolVersion::V3,
+                "4" => ProtocolVersion::V4,
+                "5" => ProtocolVersion::V5,
+                "6" => ProtocolVersion::V6,
+                "7" => ProtocolVersion::V7,
+                _ => return Err(Error::unknown_protocol_version(input)),
+            }
         })
     }
 }

src/types/quoted_string.rs

@@ -1,62 +0,0 @@
-use crate::{Error, ErrorKind, Result};
-use std::fmt;
-use std::ops::Deref;
-use std::str::{self, FromStr};
-
-/// Quoted string.
-///
-/// See: [4.2. Attribute Lists]
-///
-/// [4.2. Attribute Lists]: https://tools.ietf.org/html/rfc8216#section-4.2
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct QuotedString(String);
-
-impl QuotedString {
-    /// Makes a new `QuotedString` instance.
-    ///
-    /// # Errors
-    ///
-    /// If the given string contains any control characters or double-quote character,
-    /// this function will return an error which has the kind `ErrorKind::InvalidInput`.
-    pub fn new<T: Into<String>>(s: T) -> Result<Self> {
-        let s = s.into();
-        track_assert!(
-            !s.chars().any(|c| c.is_control() || c == '"'),
-            ErrorKind::InvalidInput
-        );
-        Ok(QuotedString(s))
-    }
-}
-
-impl Deref for QuotedString {
-    type Target = str;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl AsRef<str> for QuotedString {
-    fn as_ref(&self) -> &str {
-        &self.0
-    }
-}
-
-impl fmt::Display for QuotedString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{:?}", self.0)
-    }
-}
-
-impl FromStr for QuotedString {
-    type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        let len = s.len();
-        let bytes = s.as_bytes();
-        track_assert!(len >= 2, ErrorKind::InvalidInput);
-        track_assert_eq!(bytes[0], b'"', ErrorKind::InvalidInput);
-        track_assert_eq!(bytes[len - 1], b'"', ErrorKind::InvalidInput);
-
-        let s = unsafe { str::from_utf8_unchecked(&bytes[1..len - 1]) };
-        track!(QuotedString::new(s))
-    }
-}

src/types/session_data.rs

@@ -1,13 +0,0 @@
-use crate::types::QuotedString;
-
-/// Session data.
-///
-/// See: [4.3.4.4. EXT-X-SESSION-DATA]
-///
-/// [4.3.4.4. EXT-X-SESSION-DATA]: https://tools.ietf.org/html/rfc8216#section-4.3.4.4
-#[allow(missing_docs)]
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum SessionData {
-    Value(QuotedString),
-    Uri(QuotedString),
-}

src/types/signed_decimal_floating_point.rs

@@ -1,7 +1,7 @@
-use crate::{Error, ErrorKind, Result};
 use std::fmt;
-use std::str::{self, FromStr};
-use trackable::error::ErrorKindExt;
+use std::str::FromStr;
+
+use crate::Error;
 
 /// Signed decimal floating-point number.
 ///
@@ -9,7 +9,7 @@ use trackable::error::ErrorKindExt;
 ///
 /// [4.2. Attribute Lists]: https://tools.ietf.org/html/rfc8216#section-4.2
 #[derive(Debug, Clone, Copy, PartialEq, PartialOrd)]
-pub struct SignedDecimalFloatingPoint(f64);
+pub(crate) struct SignedDecimalFloatingPoint(f64);
 
 impl SignedDecimalFloatingPoint {
     /// Makes a new `SignedDecimalFloatingPoint` instance.
@@ -18,13 +18,16 @@ impl SignedDecimalFloatingPoint {
     ///
     /// The given value must be finite,
     /// otherwise this function will return an error that has the kind `ErrorKind::InvalidInput`.
-    pub fn new(n: f64) -> Result<Self> {
-        track_assert!(n.is_finite(), ErrorKind::InvalidInput);
-        Ok(SignedDecimalFloatingPoint(n))
+    pub fn new(n: f64) -> crate::Result<Self> {
+        if !n.is_finite() {
+            Err(Error::invalid_input())
+        } else {
+            Ok(SignedDecimalFloatingPoint(n))
+        }
     }
 
     /// Converts `DecimalFloatingPoint` to `f64`.
-    pub fn as_f64(self) -> f64 {
+    pub const fn as_f64(self) -> f64 {
         self.0
     }
 }
@@ -45,12 +48,8 @@ impl fmt::Display for SignedDecimalFloatingPoint {
 
 impl FromStr for SignedDecimalFloatingPoint {
     type Err = Error;
-    fn from_str(s: &str) -> Result<Self> {
-        track_assert!(
-            s.chars().all(|c| c.is_digit(10) || c == '.' || c == '-'),
-            ErrorKind::InvalidInput
-        );
-        let n = track!(s.parse().map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
-        Ok(SignedDecimalFloatingPoint(n))
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        SignedDecimalFloatingPoint::new(input.parse().map_err(Error::parse_float_error)?)
     }
 }

src/types/single_line_string.rs

@@ -1,55 +0,0 @@
-use crate::{ErrorKind, Result};
-use std::fmt;
-use std::ops::Deref;
-
-/// String that represents a single line in a playlist file.
-///
-/// See: [4.1. Definition of a Playlist]
-///
-/// [4.1. Definition of a Playlist]: https://tools.ietf.org/html/rfc8216#section-4.1
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct SingleLineString(String);
-
-impl SingleLineString {
-    /// Makes a new `SingleLineString` instance.
-    ///
-    /// # Errors
-    ///
-    /// If the given string contains any control characters,
-    /// this function will return an error which has the kind `ErrorKind::InvalidInput`.
-    pub fn new<T: Into<String>>(s: T) -> Result<Self> {
-        let s = s.into();
-        track_assert!(!s.chars().any(|c| c.is_control()), ErrorKind::InvalidInput);
-        Ok(SingleLineString(s))
-    }
-}
-
-impl Deref for SingleLineString {
-    type Target = str;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl AsRef<str> for SingleLineString {
-    fn as_ref(&self) -> &str {
-        &self.0
-    }
-}
-
-impl fmt::Display for SingleLineString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.0.fmt(f)
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn single_line_string() {
-        assert!(SingleLineString::new("foo").is_ok());
-        assert!(SingleLineString::new("b\rar").is_err());
-    }
-}

src/utils.rs

@@ -1,15 +1,103 @@
-use crate::{ErrorKind, Result};
-use trackable::error::ErrorKindExt;
+use crate::Error;
 
-pub fn parse_yes_or_no(s: &str) -> Result<bool> {
-    match s {
+pub(crate) fn parse_yes_or_no<T: AsRef<str>>(s: T) -> crate::Result<bool> {
+    match s.as_ref() {
         "YES" => Ok(true),
         "NO" => Ok(false),
-        _ => track_panic!(ErrorKind::InvalidInput, "Unexpected value: {:?}", s),
+        _ => Err(Error::invalid_input()),
     }
 }
 
-pub fn parse_u64(s: &str) -> Result<u64> {
-    let n = track!(s.parse().map_err(|e| ErrorKind::InvalidInput.cause(e)))?;
+pub(crate) fn parse_u64<T: AsRef<str>>(s: T) -> crate::Result<u64> {
+    let n = s.as_ref().parse().map_err(Error::unknown)?; // TODO: Error::number
     Ok(n)
 }
+
+/// According to the documentation the following characters are forbidden
+/// inside a quoted string:
+/// - carriage return (`\r`)
+/// - new line (`\n`)
+/// - double quotes (`"`)
+///
+/// Therefore it is safe to simply remove any occurence of those characters.
+/// [rfc8216#section-4.2](https://tools.ietf.org/html/rfc8216#section-4.2)
+pub(crate) fn unquote<T: ToString>(value: T) -> String {
+    value
+        .to_string()
+        .replace("\"", "")
+        .replace("\n", "")
+        .replace("\r", "")
+}
+
+/// Puts a string inside quotes.
+pub(crate) fn quote<T: ToString>(value: T) -> String {
+    // the replace is for the case, that quote is called on an already quoted string, which could
+    // cause problems!
+    format!("\"{}\"", value.to_string().replace("\"", ""))
+}
+
+/// Checks, if the given tag is at the start of the input. If this is the case, it will remove it
+/// and return the rest of the input.
+///
+/// # Error
+/// This function will return `Error::MissingTag`, if the input doesn't start with the tag, that
+/// has been passed to this function.
+pub(crate) fn tag<T>(input: &str, tag: T) -> crate::Result<&str>
+where
+    T: AsRef<str>,
+{
+    if !input.starts_with(tag.as_ref()) {
+        return Err(Error::missing_tag(tag.as_ref(), input));
+    }
+    let result = input.split_at(tag.as_ref().len()).1;
+    Ok(result)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_yes_or_no() {
+        assert!(parse_yes_or_no("YES").unwrap());
+        assert!(!parse_yes_or_no("NO").unwrap());
+        // TODO: test for error
+    }
+
+    #[test]
+    fn test_parse_u64() {
+        assert_eq!(parse_u64("1").unwrap(), 1);
+        assert_eq!(parse_u64("25").unwrap(), 25);
+        // TODO: test for error
+    }
+
+    #[test]
+    fn test_unquote() {
+        assert_eq!(unquote("\"TestValue\""), "TestValue".to_string());
+        assert_eq!(unquote("\"TestValue\n\""), "TestValue".to_string());
+        assert_eq!(unquote("\"TestValue\n\r\""), "TestValue".to_string());
+    }
+
+    #[test]
+    fn test_quote() {
+        assert_eq!(quote("value"), "\"value\"".to_string());
+        assert_eq!(quote("\"value\""), "\"value\"".to_string());
+    }
+
+    #[test]
+    fn test_tag() {
+        let input = "HelloMyFriendThisIsASampleString";
+
+        let input = tag(input, "Hello").unwrap();
+        assert_eq!(input, "MyFriendThisIsASampleString");
+
+        let input = tag(input, "My").unwrap();
+        assert_eq!(input, "FriendThisIsASampleString");
+
+        let input = tag(input, "FriendThisIs").unwrap();
+        assert_eq!(input, "ASampleString");
+
+        let input = tag(input, "A").unwrap();
+        assert_eq!(input, "SampleString");
+    }
+}

tests/playlist.rs

@@ -0,0 +1,46 @@
+//! Credits go to
+//! - https://github.com/globocom/m3u8/blob/master/tests/playlists.py
+use hls_m3u8::tags::*;
+use hls_m3u8::MediaPlaylist;
+
+use std::time::Duration;
+
+#[test]
+fn test_simple_playlist() {
+    let playlist = r#"
+    #EXTM3U
+    #EXT-X-TARGETDURATION:5220
+    #EXTINF:0,
+    http://media.example.com/entire1.ts
+    #EXTINF:5220,
+    http://media.example.com/entire2.ts
+    #EXT-X-ENDLIST"#;
+
+    let media_playlist = playlist.parse::<MediaPlaylist>().unwrap();
+    assert_eq!(
+        media_playlist.target_duration_tag(),
+        ExtXTargetDuration::new(Duration::from_secs(5220))
+    );
+
+    assert_eq!(media_playlist.segments().len(), 2);
+
+    assert_eq!(
+        media_playlist.segments()[0].inf_tag(),
+        &ExtInf::new(Duration::from_secs(0))
+    );
+
+    assert_eq!(
+        media_playlist.segments()[1].inf_tag(),
+        &ExtInf::new(Duration::from_secs(5220))
+    );
+
+    assert_eq!(
+        media_playlist.segments()[0].uri(),
+        &"http://media.example.com/entire1.ts".parse().unwrap()
+    );
+
+    assert_eq!(
+        media_playlist.segments()[1].uri(),
+        &"http://media.example.com/entire2.ts".parse().unwrap()
+    );
+}