src

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git clone git://code.dwrz.net/src
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runewidth_posix.go (1481B)

      1 //go:build !windows && !js && !appengine
      2 // +build !windows,!js,!appengine
      3 
      4 package runewidth
      5 
      6 import (
      7 	"os"
      8 	"regexp"
      9 	"strings"
     10 )
     11 
     12 var reLoc = regexp.MustCompile(`^[a-z][a-z][a-z]?(?:_[A-Z][A-Z])?\.(.+)`)
     13 
     14 var mblenTable = map[string]int{
     15 	"utf-8":   6,
     16 	"utf8":    6,
     17 	"jis":     8,
     18 	"eucjp":   3,
     19 	"euckr":   2,
     20 	"euccn":   2,
     21 	"sjis":    2,
     22 	"cp932":   2,
     23 	"cp51932": 2,
     24 	"cp936":   2,
     25 	"cp949":   2,
     26 	"cp950":   2,
     27 	"big5":    2,
     28 	"gbk":     2,
     29 	"gb2312":  2,
     30 }
     31 
     32 func isEastAsian(locale string) bool {
     33 	charset := strings.ToLower(locale)
     34 	r := reLoc.FindStringSubmatch(locale)
     35 	if len(r) == 2 {
     36 		charset = strings.ToLower(r[1])
     37 	}
     38 
     39 	if strings.HasSuffix(charset, "@cjk_narrow") {
     40 		return false
     41 	}
     42 
     43 	for pos, b := range []byte(charset) {
     44 		if b == '@' {
     45 			charset = charset[:pos]
     46 			break
     47 		}
     48 	}
     49 	max := 1
     50 	if m, ok := mblenTable[charset]; ok {
     51 		max = m
     52 	}
     53 	if max > 1 && (charset[0] != 'u' ||
     54 		strings.HasPrefix(locale, "ja") ||
     55 		strings.HasPrefix(locale, "ko") ||
     56 		strings.HasPrefix(locale, "zh")) {
     57 		return true
     58 	}
     59 	return false
     60 }
     61 
     62 // IsEastAsian return true if the current locale is CJK
     63 func IsEastAsian() bool {
     64 	locale := os.Getenv("LC_ALL")
     65 	if locale == "" {
     66 		locale = os.Getenv("LC_CTYPE")
     67 	}
     68 	if locale == "" {
     69 		locale = os.Getenv("LANG")
     70 	}
     71 
     72 	// ignore C locale
     73 	if locale == "POSIX" || locale == "C" {
     74 		return false
     75 	}
     76 	if len(locale) > 1 && locale[0] == 'C' && (locale[1] == '.' || locale[1] == '-') {
     77 		return false
     78 	}
     79 
     80 	return isEastAsian(locale)
     81 }