podman

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