69 lines
1.2 KiB
Go
69 lines
1.2 KiB
Go
// +build !windows,!js
|
|
|
|
package runewidth
|
|
|
|
import (
|
|
"os"
|
|
"regexp"
|
|
"strings"
|
|
)
|
|
|
|
var reLoc = regexp.MustCompile(`^[a-z][a-z][a-z]?(?:_[A-Z][A-Z])?\.(.+)`)
|
|
|
|
func IsEastAsian() bool {
|
|
locale := os.Getenv("LC_CTYPE")
|
|
if locale == "" {
|
|
locale = os.Getenv("LANG")
|
|
}
|
|
|
|
// ignore C locale
|
|
if locale == "POSIX" || locale == "C" {
|
|
return false
|
|
}
|
|
if len(locale) > 1 && locale[0] == 'C' && (locale[1] == '.' || locale[1] == '-') {
|
|
return false
|
|
}
|
|
|
|
charset := strings.ToLower(locale)
|
|
r := reLoc.FindStringSubmatch(locale)
|
|
if len(r) == 2 {
|
|
charset = strings.ToLower(r[1])
|
|
}
|
|
|
|
if strings.HasSuffix(charset, "@cjk_narrow") {
|
|
return false
|
|
}
|
|
|
|
for pos, b := range []byte(charset) {
|
|
if b == '@' {
|
|
charset = charset[:pos]
|
|
break
|
|
}
|
|
}
|
|
|
|
mbc_max := 1
|
|
switch charset {
|
|
case "utf-8", "utf8":
|
|
mbc_max = 6
|
|
case "jis":
|
|
mbc_max = 8
|
|
case "eucjp":
|
|
mbc_max = 3
|
|
case "euckr", "euccn":
|
|
mbc_max = 2
|
|
case "sjis", "cp932", "cp51932", "cp936", "cp949", "cp950":
|
|
mbc_max = 2
|
|
case "big5":
|
|
mbc_max = 2
|
|
case "gbk", "gb2312":
|
|
mbc_max = 2
|
|
}
|
|
|
|
if mbc_max > 1 && (charset[0] != 'u' ||
|
|
strings.HasPrefix(locale, "ja") ||
|
|
strings.HasPrefix(locale, "ko") ||
|
|
strings.HasPrefix(locale, "zh")) {
|
|
return true
|
|
}
|
|
return false
|
|
}
|