forgejo/modules/emoji/emoji.go
flynnnnnnnnnn e81ccc406b
Implement FSFE REUSE for golang files (#21840)
Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>
2022-11-27 18:20:29 +00:00

187 lines
4.5 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// Copyright 2015 Kenneth Shaw
// SPDX-License-Identifier: MIT
package emoji
import (
"io"
"sort"
"strings"
"sync"
)
// Gemoji is a set of emoji data.
type Gemoji []Emoji
// Emoji represents a single emoji and associated data.
type Emoji struct {
Emoji string
Description string
Aliases []string
UnicodeVersion string
SkinTones bool
}
var (
// codeMap provides a map of the emoji unicode code to its emoji data.
codeMap map[string]int
// aliasMap provides a map of the alias to its emoji data.
aliasMap map[string]int
// emptyReplacer is the string replacer for emoji codes.
emptyReplacer *strings.Replacer
// codeReplacer is the string replacer for emoji codes.
codeReplacer *strings.Replacer
// aliasReplacer is the string replacer for emoji aliases.
aliasReplacer *strings.Replacer
once sync.Once
)
func loadMap() {
once.Do(func() {
// initialize
codeMap = make(map[string]int, len(GemojiData))
aliasMap = make(map[string]int, len(GemojiData))
// process emoji codes and aliases
codePairs := make([]string, 0)
emptyPairs := make([]string, 0)
aliasPairs := make([]string, 0)
// sort from largest to small so we match combined emoji first
sort.Slice(GemojiData, func(i, j int) bool {
return len(GemojiData[i].Emoji) > len(GemojiData[j].Emoji)
})
for i, e := range GemojiData {
if e.Emoji == "" || len(e.Aliases) == 0 {
continue
}
// setup codes
codeMap[e.Emoji] = i
codePairs = append(codePairs, e.Emoji, ":"+e.Aliases[0]+":")
emptyPairs = append(emptyPairs, e.Emoji, e.Emoji)
// setup aliases
for _, a := range e.Aliases {
if a == "" {
continue
}
aliasMap[a] = i
aliasPairs = append(aliasPairs, ":"+a+":", e.Emoji)
}
}
// create replacers
emptyReplacer = strings.NewReplacer(emptyPairs...)
codeReplacer = strings.NewReplacer(codePairs...)
aliasReplacer = strings.NewReplacer(aliasPairs...)
})
}
// FromCode retrieves the emoji data based on the provided unicode code (ie,
// "\u2618" will return the Gemoji data for "shamrock").
func FromCode(code string) *Emoji {
loadMap()
i, ok := codeMap[code]
if !ok {
return nil
}
return &GemojiData[i]
}
// FromAlias retrieves the emoji data based on the provided alias in the form
// "alias" or ":alias:" (ie, "shamrock" or ":shamrock:" will return the Gemoji
// data for "shamrock").
func FromAlias(alias string) *Emoji {
loadMap()
if strings.HasPrefix(alias, ":") && strings.HasSuffix(alias, ":") {
alias = alias[1 : len(alias)-1]
}
i, ok := aliasMap[alias]
if !ok {
return nil
}
return &GemojiData[i]
}
// ReplaceCodes replaces all emoji codes with the first corresponding emoji
// alias (in the form of ":alias:") (ie, "\u2618" will be converted to
// ":shamrock:").
func ReplaceCodes(s string) string {
loadMap()
return codeReplacer.Replace(s)
}
// ReplaceAliases replaces all aliases of the form ":alias:" with its
// corresponding unicode value.
func ReplaceAliases(s string) string {
loadMap()
return aliasReplacer.Replace(s)
}
type rememberSecondWriteWriter struct {
pos int
idx int
end int
writecount int
}
func (n *rememberSecondWriteWriter) Write(p []byte) (int, error) {
n.writecount++
if n.writecount == 2 {
n.idx = n.pos
n.end = n.pos + len(p)
n.pos += len(p)
return len(p), io.EOF
}
n.pos += len(p)
return len(p), nil
}
func (n *rememberSecondWriteWriter) WriteString(s string) (int, error) {
n.writecount++
if n.writecount == 2 {
n.idx = n.pos
n.end = n.pos + len(s)
n.pos += len(s)
return len(s), io.EOF
}
n.pos += len(s)
return len(s), nil
}
// FindEmojiSubmatchIndex returns index pair of longest emoji in a string
func FindEmojiSubmatchIndex(s string) []int {
loadMap()
secondWriteWriter := rememberSecondWriteWriter{}
// A faster and clean implementation would copy the trie tree formation in strings.NewReplacer but
// we can be lazy here.
//
// The implementation of strings.Replacer.WriteString is such that the first index of the emoji
// submatch is simply the second thing that is written to WriteString in the writer.
//
// Therefore we can simply take the index of the second write as our first emoji
//
// FIXME: just copy the trie implementation from strings.NewReplacer
_, _ = emptyReplacer.WriteString(&secondWriteWriter, s)
// if we wrote less than twice then we never "replaced"
if secondWriteWriter.writecount < 2 {
return nil
}
return []int{secondWriteWriter.idx, secondWriteWriter.end}
}