kitty/tools/utils/regexp.go
2022-11-14 15:42:01 +05:30

52 lines
1.2 KiB
Go

// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
package utils
import (
"fmt"
"regexp"
"strings"
"sync"
)
var _ = fmt.Print
var pat_cache = map[string]*regexp.Regexp{}
var pat_cache_lock = sync.RWMutex{}
func ReplaceAll(pat, str string, repl func(full_match string, groupdict map[string]string) string) string {
pat_cache_lock.RLock()
cpat := pat_cache[pat]
pat_cache_lock.RUnlock()
if cpat == nil {
cpat = regexp.MustCompile(pat)
pat_cache_lock.Lock()
pat_cache[pat] = cpat
pat_cache_lock.Unlock()
}
result := strings.Builder{}
result.Grow(len(str) + 256)
last_index := 0
matches := cpat.FindAllStringSubmatchIndex(str, -1)
names := cpat.SubexpNames()
for _, v := range matches {
match_start, match_end := v[0], v[1]
full_match := str[match_start:match_end]
groupdict := make(map[string]string, len(names))
for i, name := range names {
if i == 0 {
continue
}
idx := 2 * i
if v[idx] > -1 && v[idx+1] > -1 {
groupdict[name] = str[v[idx]:v[idx+1]]
}
}
result.WriteString(str[last_index:match_start])
result.WriteString(repl(full_match, groupdict))
last_index = match_end
}
result.WriteString(str[last_index:])
return result.String()
}