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gitea/modules/emoji/emoji.go

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3.7 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// Copyright 2015 Kenneth Shaw
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package emoji
import (
"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
// 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)
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]+":")
// setup aliases
for _, a := range e.Aliases {
if a == "" {
continue
}
aliasMap[a] = i
aliasPairs = append(aliasPairs, ":"+a+":", e.Emoji)
}
}
// create replacers
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)
}
// FindEmojiSubmatchIndex returns index pair of longest emoji in a string
func FindEmojiSubmatchIndex(s string) []int {
loadMap()
found := make(map[int]int)
keys := make([]int, 0)
//see if there are any emoji in string before looking for position of specific ones
//no performance difference when there is a match but 10x faster when there are not
if s == ReplaceCodes(s) {
return nil
}
// get index of first emoji occurrence while also checking for longest combination
for j := range GemojiData {
i := strings.Index(s, GemojiData[j].Emoji)
if i != -1 {
if _, ok := found[i]; !ok {
if len(keys) == 0 || i < keys[0] {
found[i] = j
keys = []int{i}
}
if i == 0 {
break
}
}
}
}
if len(keys) > 0 {
index := keys[0]
return []int{index, index + len(GemojiData[found[index]].Emoji)}
}
return nil
}