mirror of
https://github.com/superseriousbusiness/gotosocial
synced 2024-11-10 23:14:17 +00:00
134 lines
4 KiB
Go
134 lines
4 KiB
Go
/*
|
|
GoToSocial
|
|
Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Affero General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU Affero General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Affero General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
package util
|
|
|
|
import (
|
|
"unicode"
|
|
"unicode/utf8"
|
|
|
|
"github.com/superseriousbusiness/gotosocial/internal/regexes"
|
|
)
|
|
|
|
const (
|
|
maximumHashtagLength = 30
|
|
)
|
|
|
|
// DeriveMentionNamesFromText takes a plaintext (ie., not html-formatted) text,
|
|
// and applies a regex to it to return a deduplicated list of account names
|
|
// mentioned in that text, in the format "@user@example.org" or "@username" for
|
|
// local users.
|
|
func DeriveMentionNamesFromText(text string) []string {
|
|
mentionedAccounts := []string{}
|
|
for _, m := range regexes.MentionFinder.FindAllStringSubmatch(text, -1) {
|
|
mentionedAccounts = append(mentionedAccounts, m[1])
|
|
}
|
|
return UniqueStrings(mentionedAccounts)
|
|
}
|
|
|
|
type Pair[A, B any] struct {
|
|
First A
|
|
Second B
|
|
}
|
|
|
|
// Byte index in original string
|
|
// `First` includes `#`.
|
|
type Span = Pair[int, int]
|
|
|
|
// Takes a plaintext (ie., not HTML-formatted) text,
|
|
// and returns a slice of unique hashtags.
|
|
func DeriveHashtagsFromText(text string) []string {
|
|
tagsMap := make(map[string]bool)
|
|
tags := []string{}
|
|
|
|
for _, v := range FindHashtagSpansInText(text) {
|
|
t := text[v.First+1 : v.Second]
|
|
if _, value := tagsMap[t]; !value {
|
|
tagsMap[t] = true
|
|
tags = append(tags, t)
|
|
}
|
|
}
|
|
|
|
return tags
|
|
}
|
|
|
|
// Takes a plaintext (ie., not HTML-formatted) text,
|
|
// and returns a list of pairs of indices into the original string, where
|
|
// hashtags are located.
|
|
func FindHashtagSpansInText(text string) []Span {
|
|
tags := []Span{}
|
|
start := 0
|
|
// Keep one rune of lookbehind.
|
|
prev := ' '
|
|
inTag := false
|
|
|
|
for i, r := range text {
|
|
if r == '#' && IsHashtagBoundary(prev) {
|
|
// Start of hashtag.
|
|
inTag = true
|
|
start = i
|
|
} else if inTag && !IsPermittedInHashtag(r) && !IsHashtagBoundary(r) {
|
|
// Inside the hashtag, but it was a phoney, gottem.
|
|
inTag = false
|
|
} else if inTag && IsHashtagBoundary(r) {
|
|
// End of hashtag.
|
|
inTag = false
|
|
appendTag(&tags, text, start, i)
|
|
} else if irl := i + utf8.RuneLen(r); inTag && irl == len(text) {
|
|
// End of text.
|
|
appendTag(&tags, text, start, irl)
|
|
}
|
|
|
|
prev = r
|
|
}
|
|
|
|
return tags
|
|
}
|
|
|
|
func appendTag(tags *[]Span, text string, start int, end int) {
|
|
l := end - start - 1
|
|
// This check could be moved out into the parsing loop if necessary!
|
|
if 0 < l && l <= maximumHashtagLength {
|
|
*tags = append(*tags, Span{First: start, Second: end})
|
|
}
|
|
}
|
|
|
|
// DeriveEmojisFromText takes a plaintext (ie., not html-formatted) text,
|
|
// and applies a regex to it to return a deduplicated list of emojis
|
|
// used in that text, without the surrounding `::`
|
|
func DeriveEmojisFromText(text string) []string {
|
|
emojis := []string{}
|
|
for _, m := range regexes.EmojiFinder.FindAllStringSubmatch(text, -1) {
|
|
emojis = append(emojis, m[1])
|
|
}
|
|
return UniqueStrings(emojis)
|
|
}
|
|
|
|
func IsPermittedInHashtag(r rune) bool {
|
|
return unicode.IsLetter(r) || unicode.IsNumber(r)
|
|
}
|
|
|
|
// Decides where to break before or after a hashtag.
|
|
func IsHashtagBoundary(r rune) bool {
|
|
return r == '#' || // `###lol` should work
|
|
unicode.IsSpace(r) || // All kinds of Unicode whitespace.
|
|
unicode.IsControl(r) || // All kinds of control characters, like tab.
|
|
// Most kinds of punctuation except "Pc" ("Punctuation, connecting", like `_`).
|
|
// But `someurl/#fragment` should not match, neither should HTML entities like `#`.
|
|
('/' != r && '&' != r && !unicode.Is(unicode.Categories["Pc"], r) && unicode.IsPunct(r))
|
|
}
|