improve readability

src/master_playlist.rs

@@ -10,7 +10,7 @@ use crate::tags::{
     ExtXVersion, VariantStream,
 };
 use crate::types::{ClosedCaptions, MediaType, ProtocolVersion};
-use crate::utils::tag;
+use crate::utils::{tag, BoolExt};
 use crate::{Error, RequiredVersion};
 
 /// The master playlist describes all of the available variants for your
@@ -97,6 +97,7 @@ use crate::{Error, RequiredVersion};
 #[derive(Builder, Default, Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[builder(build_fn(validate = "Self::validate"))]
 #[builder(setter(into, strip_option))]
+#[non_exhaustive]
 pub struct MasterPlaylist {
     /// Indicates that all media samples in a [`MediaSegment`] can be
     /// decoded without information from other segments.
@@ -167,8 +168,6 @@ pub struct MasterPlaylist {
     /// This field is optional.
     #[builder(default)]
     pub unknown_tags: Vec<String>,
-    #[builder(default, field(private))]
-    __non_exhaustive: (),
 }
 
 impl MasterPlaylist {
@@ -277,13 +276,8 @@ impl MasterPlaylist {
 impl RequiredVersion for MasterPlaylist {
     fn required_version(&self) -> ProtocolVersion {
         required_version![
-            {
-                if self.has_independent_segments {
-                    Some(ExtXIndependentSegments)
-                } else {
-                    None
-                }
-            },
+            self.has_independent_segments
+                .athen_some(ExtXIndependentSegments),
             self.start,
             self.media,
             self.variant_streams,
@@ -403,13 +397,9 @@ impl RequiredVersion for MasterPlaylistBuilder {
         //       not for Option<Option<T>>)
         // https://github.com/rust-lang/chalk/issues/12
         required_version![
-            {
-                if self.has_independent_segments.unwrap_or(false) {
-                    Some(ExtXIndependentSegments)
-                } else {
-                    None
-                }
-            },
+            self.has_independent_segments
+                .unwrap_or(false)
+                .athen_some(ExtXIndependentSegments),
             self.start.flatten(),
             self.media,
             self.variant_streams,

src/media_playlist.rs

@@ -11,8 +11,10 @@ use crate::tags::{
     ExtM3u, ExtXDiscontinuitySequence, ExtXEndList, ExtXIFramesOnly, ExtXIndependentSegments,
     ExtXKey, ExtXMediaSequence, ExtXStart, ExtXTargetDuration, ExtXVersion,
 };
-use crate::types::{EncryptionMethod, PlaylistType, ProtocolVersion};
-use crate::utils::tag;
+use crate::types::{
+    DecryptionKey, EncryptionMethod, InitializationVector, KeyFormat, PlaylistType, ProtocolVersion,
+};
+use crate::utils::{tag, BoolExt};
 use crate::{Error, RequiredVersion};
 
 /// Media playlist.
@@ -274,13 +276,7 @@ impl MediaPlaylistBuilder {
         // insert all explictly numbered segments into the result
         let mut result_segments = segments
             .iter()
-            .filter_map(|(_, s)| {
-                if s.explicit_number {
-                    Some((s.number, s.clone()))
-                } else {
-                    None
-                }
-            })
+            .filter_map(|(_, s)| s.explicit_number.athen(|| (s.number, s.clone())))
             .collect::<BTreeMap<_, _>>();
 
         // no segment should exist before the sequence_number
@@ -345,45 +341,19 @@ impl RequiredVersion for MediaPlaylistBuilder {
     fn required_version(&self) -> ProtocolVersion {
         required_version![
             self.target_duration.map(ExtXTargetDuration),
-            {
-                if self.media_sequence.unwrap_or(0) != 0 {
-                    Some(ExtXMediaSequence(self.media_sequence.unwrap_or(0)))
-                } else {
-                    None
-                }
-            },
-            {
-                if self.discontinuity_sequence.unwrap_or(0) != 0 {
-                    Some(ExtXDiscontinuitySequence(
-                        self.discontinuity_sequence.unwrap_or(0),
-                    ))
-                } else {
-                    None
-                }
-            },
+            (self.media_sequence.unwrap_or(0) != 0)
+                .athen(|| ExtXMediaSequence(self.media_sequence.unwrap_or(0))),
+            (self.discontinuity_sequence.unwrap_or(0) != 0)
+                .athen(|| ExtXDiscontinuitySequence(self.discontinuity_sequence.unwrap_or(0))),
             self.playlist_type,
-            {
-                if self.has_i_frames_only.unwrap_or(false) {
-                    Some(ExtXIFramesOnly)
-                } else {
-                    None
-                }
-            },
-            {
-                if self.has_independent_segments.unwrap_or(false) {
-                    Some(ExtXIndependentSegments)
-                } else {
-                    None
-                }
-            },
+            self.has_i_frames_only
+                .unwrap_or(false)
+                .athen_some(ExtXIFramesOnly),
+            self.has_independent_segments
+                .unwrap_or(false)
+                .athen_some(ExtXIndependentSegments),
             self.start,
-            {
-                if self.has_end_list.unwrap_or(false) {
-                    Some(ExtXEndList)
-                } else {
-                    None
-                }
-            },
+            self.has_end_list.unwrap_or(false).athen_some(ExtXEndList),
             self.segments
         ]
     }
@@ -406,43 +376,15 @@ impl RequiredVersion for MediaPlaylist {
     fn required_version(&self) -> ProtocolVersion {
         required_version![
             ExtXTargetDuration(self.target_duration),
-            {
-                if self.media_sequence != 0 {
-                    Some(ExtXMediaSequence(self.media_sequence))
-                } else {
-                    None
-                }
-            },
-            {
-                if self.discontinuity_sequence != 0 {
-                    Some(ExtXDiscontinuitySequence(self.discontinuity_sequence))
-                } else {
-                    None
-                }
-            },
+            (self.media_sequence != 0).athen(|| ExtXMediaSequence(self.media_sequence)),
+            (self.discontinuity_sequence != 0)
+                .athen(|| ExtXDiscontinuitySequence(self.discontinuity_sequence)),
             self.playlist_type,
-            {
-                if self.has_i_frames_only {
-                    Some(ExtXIFramesOnly)
-                } else {
-                    None
-                }
-            },
-            {
-                if self.has_independent_segments {
-                    Some(ExtXIndependentSegments)
-                } else {
-                    None
-                }
-            },
+            self.has_i_frames_only.athen_some(ExtXIFramesOnly),
+            self.has_independent_segments
+                .athen_some(ExtXIndependentSegments),
             self.start,
-            {
-                if self.has_end_list {
-                    Some(ExtXEndList)
-                } else {
-                    None
-                }
-            },
+            self.has_end_list.athen_some(ExtXEndList),
             self.segments
         ]
     }

src/utils.rs

@@ -1,6 +1,45 @@
 use crate::Error;
 use core::iter;
 
+/// This is an extension trait that adds the below method to `bool`.
+/// Those methods are already planned for the standard library, but are not
+/// stable at the time of writing this comment.
+///
+/// The current status can be seen here:
+/// <https://github.com/rust-lang/rust/issues/64260>
+///
+/// This trait exists to allow publishing a new version (requires stable
+/// release) and the functions are prefixed with an `a` to prevent naming
+/// conflicts with the coming std functions.
+// TODO: replace this trait with std version as soon as it is stabilized
+pub(crate) trait BoolExt {
+    #[must_use]
+    fn athen_some<T>(self, t: T) -> Option<T>;
+
+    #[must_use]
+    fn athen<T, F: FnOnce() -> T>(self, f: F) -> Option<T>;
+}
+
+impl BoolExt for bool {
+    #[inline]
+    fn athen_some<T>(self, t: T) -> Option<T> {
+        if self {
+            Some(t)
+        } else {
+            None
+        }
+    }
+
+    #[inline]
+    fn athen<T, F: FnOnce() -> T>(self, f: F) -> Option<T> {
+        if self {
+            Some(f())
+        } else {
+            None
+        }
+    }
+}
+
 macro_rules! required_version {
     ( $( $tag:expr ),* ) => {
         ::core::iter::empty()