121 lines
2.2 KiB
Go
121 lines
2.2 KiB
Go
// Copyright 2015 Huan Du. All rights reserved.
|
|
// Licensed under the MIT license that can be found in the LICENSE file.
|
|
|
|
package xstrings
|
|
|
|
import (
|
|
"unicode"
|
|
"unicode/utf8"
|
|
)
|
|
|
|
// Get str's utf8 rune length.
|
|
func Len(str string) int {
|
|
return utf8.RuneCountInString(str)
|
|
}
|
|
|
|
// Count number of words in a string.
|
|
//
|
|
// Word is defined as a locale dependent string containing alphabetic characters,
|
|
// which may also contain but not start with `'` and `-` characters.
|
|
func WordCount(str string) int {
|
|
var r rune
|
|
var size, n int
|
|
|
|
inWord := false
|
|
|
|
for len(str) > 0 {
|
|
r, size = utf8.DecodeRuneInString(str)
|
|
|
|
switch {
|
|
case isAlphabet(r):
|
|
if !inWord {
|
|
inWord = true
|
|
n++
|
|
}
|
|
|
|
case inWord && (r == '\'' || r == '-'):
|
|
// Still in word.
|
|
|
|
default:
|
|
inWord = false
|
|
}
|
|
|
|
str = str[size:]
|
|
}
|
|
|
|
return n
|
|
}
|
|
|
|
const minCJKCharacter = '\u3400'
|
|
|
|
// Checks r is a letter but not CJK character.
|
|
func isAlphabet(r rune) bool {
|
|
if !unicode.IsLetter(r) {
|
|
return false
|
|
}
|
|
|
|
switch {
|
|
// Quick check for non-CJK character.
|
|
case r < minCJKCharacter:
|
|
return true
|
|
|
|
// Common CJK characters.
|
|
case r >= '\u4E00' && r <= '\u9FCC':
|
|
return false
|
|
|
|
// Rare CJK characters.
|
|
case r >= '\u3400' && r <= '\u4D85':
|
|
return false
|
|
|
|
// Rare and historic CJK characters.
|
|
case r >= '\U00020000' && r <= '\U0002B81D':
|
|
return false
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
// Width returns string width in monotype font.
|
|
// Multi-byte characters are usually twice the width of single byte characters.
|
|
//
|
|
// Algorithm comes from `mb_strwidth` in PHP.
|
|
// http://php.net/manual/en/function.mb-strwidth.php
|
|
func Width(str string) int {
|
|
var r rune
|
|
var size, n int
|
|
|
|
for len(str) > 0 {
|
|
r, size = utf8.DecodeRuneInString(str)
|
|
n += RuneWidth(r)
|
|
str = str[size:]
|
|
}
|
|
|
|
return n
|
|
}
|
|
|
|
// RuneWidth returns character width in monotype font.
|
|
// Multi-byte characters are usually twice the width of single byte characters.
|
|
//
|
|
// Algorithm comes from `mb_strwidth` in PHP.
|
|
// http://php.net/manual/en/function.mb-strwidth.php
|
|
func RuneWidth(r rune) int {
|
|
switch {
|
|
case r == utf8.RuneError || r < '\x20':
|
|
return 0
|
|
|
|
case '\x20' <= r && r < '\u2000':
|
|
return 1
|
|
|
|
case '\u2000' <= r && r < '\uFF61':
|
|
return 2
|
|
|
|
case '\uFF61' <= r && r < '\uFFA0':
|
|
return 1
|
|
|
|
case '\uFFA0' <= r:
|
|
return 2
|
|
}
|
|
|
|
return 0
|
|
}
|