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Diffstat (limited to 'vendor/github.com/huandu/xstrings/translate.go')
| -rw-r--r-- | vendor/github.com/huandu/xstrings/translate.go | 552 |
1 files changed, 0 insertions, 552 deletions
diff --git a/vendor/github.com/huandu/xstrings/translate.go b/vendor/github.com/huandu/xstrings/translate.go deleted file mode 100644 index 1fac6a00b..000000000 --- a/vendor/github.com/huandu/xstrings/translate.go +++ /dev/null @@ -1,552 +0,0 @@ -// 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" -) - -type runeRangeMap struct { - FromLo rune // Lower bound of range map. - FromHi rune // An inclusive higher bound of range map. - ToLo rune - ToHi rune -} - -type runeDict struct { - Dict [unicode.MaxASCII + 1]rune -} - -type runeMap map[rune]rune - -// Translator can translate string with pre-compiled from and to patterns. -// If a from/to pattern pair needs to be used more than once, it's recommended -// to create a Translator and reuse it. -type Translator struct { - quickDict *runeDict // A quick dictionary to look up rune by index. Only available for latin runes. - runeMap runeMap // Rune map for translation. - ranges []*runeRangeMap // Ranges of runes. - mappedRune rune // If mappedRune >= 0, all matched runes are translated to the mappedRune. - reverted bool // If to pattern is empty, all matched characters will be deleted. - hasPattern bool -} - -// NewTranslator creates new Translator through a from/to pattern pair. -func NewTranslator(from, to string) *Translator { - tr := &Translator{} - - if from == "" { - return tr - } - - reverted := from[0] == '^' - deletion := len(to) == 0 - - if reverted { - from = from[1:] - } - - var fromStart, fromEnd, fromRangeStep rune - var toStart, toEnd, toRangeStep rune - var fromRangeSize, toRangeSize rune - var singleRunes []rune - - // Update the to rune range. - updateRange := func() { - // No more rune to read in the to rune pattern. - if toEnd == utf8.RuneError { - return - } - - if toRangeStep == 0 { - to, toStart, toEnd, toRangeStep = nextRuneRange(to, toEnd) - return - } - - // Current range is not empty. Consume 1 rune from start. - if toStart != toEnd { - toStart += toRangeStep - return - } - - // No more rune. Repeat the last rune. - if to == "" { - toEnd = utf8.RuneError - return - } - - // Both start and end are used. Read two more runes from the to pattern. - to, toStart, toEnd, toRangeStep = nextRuneRange(to, utf8.RuneError) - } - - if deletion { - toStart = utf8.RuneError - toEnd = utf8.RuneError - } else { - // If from pattern is reverted, only the last rune in the to pattern will be used. - if reverted { - var size int - - for len(to) > 0 { - toStart, size = utf8.DecodeRuneInString(to) - to = to[size:] - } - - toEnd = utf8.RuneError - } else { - to, toStart, toEnd, toRangeStep = nextRuneRange(to, utf8.RuneError) - } - } - - fromEnd = utf8.RuneError - - for len(from) > 0 { - from, fromStart, fromEnd, fromRangeStep = nextRuneRange(from, fromEnd) - - // fromStart is a single character. Just map it with a rune in the to pattern. - if fromRangeStep == 0 { - singleRunes = tr.addRune(fromStart, toStart, singleRunes) - updateRange() - continue - } - - for toEnd != utf8.RuneError && fromStart != fromEnd { - // If mapped rune is a single character instead of a range, simply shift first - // rune in the range. - if toRangeStep == 0 { - singleRunes = tr.addRune(fromStart, toStart, singleRunes) - updateRange() - fromStart += fromRangeStep - continue - } - - fromRangeSize = (fromEnd - fromStart) * fromRangeStep - toRangeSize = (toEnd - toStart) * toRangeStep - - // Not enough runes in the to pattern. Need to read more. - if fromRangeSize > toRangeSize { - fromStart, toStart = tr.addRuneRange(fromStart, fromStart+toRangeSize*fromRangeStep, toStart, toEnd, singleRunes) - fromStart += fromRangeStep - updateRange() - - // Edge case: If fromRangeSize == toRangeSize + 1, the last fromStart value needs be considered - // as a single rune. - if fromStart == fromEnd { - singleRunes = tr.addRune(fromStart, toStart, singleRunes) - updateRange() - } - - continue - } - - fromStart, toStart = tr.addRuneRange(fromStart, fromEnd, toStart, toStart+fromRangeSize*toRangeStep, singleRunes) - updateRange() - break - } - - if fromStart == fromEnd { - fromEnd = utf8.RuneError - continue - } - - _, toStart = tr.addRuneRange(fromStart, fromEnd, toStart, toStart, singleRunes) - fromEnd = utf8.RuneError - } - - if fromEnd != utf8.RuneError { - tr.addRune(fromEnd, toStart, singleRunes) - } - - tr.reverted = reverted - tr.mappedRune = -1 - tr.hasPattern = true - - // Translate RuneError only if in deletion or reverted mode. - if deletion || reverted { - tr.mappedRune = toStart - } - - return tr -} - -func (tr *Translator) addRune(from, to rune, singleRunes []rune) []rune { - if from <= unicode.MaxASCII { - if tr.quickDict == nil { - tr.quickDict = &runeDict{} - } - - tr.quickDict.Dict[from] = to - } else { - if tr.runeMap == nil { - tr.runeMap = make(runeMap) - } - - tr.runeMap[from] = to - } - - singleRunes = append(singleRunes, from) - return singleRunes -} - -func (tr *Translator) addRuneRange(fromLo, fromHi, toLo, toHi rune, singleRunes []rune) (rune, rune) { - var r rune - var rrm *runeRangeMap - - if fromLo < fromHi { - rrm = &runeRangeMap{ - FromLo: fromLo, - FromHi: fromHi, - ToLo: toLo, - ToHi: toHi, - } - } else { - rrm = &runeRangeMap{ - FromLo: fromHi, - FromHi: fromLo, - ToLo: toHi, - ToHi: toLo, - } - } - - // If there is any single rune conflicts with this rune range, clear single rune record. - for _, r = range singleRunes { - if rrm.FromLo <= r && r <= rrm.FromHi { - if r <= unicode.MaxASCII { - tr.quickDict.Dict[r] = 0 - } else { - delete(tr.runeMap, r) - } - } - } - - tr.ranges = append(tr.ranges, rrm) - return fromHi, toHi -} - -func nextRuneRange(str string, last rune) (remaining string, start, end rune, rangeStep rune) { - var r rune - var size int - - remaining = str - escaping := false - isRange := false - - for len(remaining) > 0 { - r, size = utf8.DecodeRuneInString(remaining) - remaining = remaining[size:] - - // Parse special characters. - if !escaping { - if r == '\\' { - escaping = true - continue - } - - if r == '-' { - // Ignore slash at beginning of string. - if last == utf8.RuneError { - continue - } - - start = last - isRange = true - continue - } - } - - escaping = false - - if last != utf8.RuneError { - // This is a range which start and end are the same. - // Considier it as a normal character. - if isRange && last == r { - isRange = false - continue - } - - start = last - end = r - - if isRange { - if start < end { - rangeStep = 1 - } else { - rangeStep = -1 - } - } - - return - } - - last = r - } - - start = last - end = utf8.RuneError - return -} - -// Translate str with a from/to pattern pair. -// -// See comment in Translate function for usage and samples. -func (tr *Translator) Translate(str string) string { - if !tr.hasPattern || str == "" { - return str - } - - var r rune - var size int - var needTr bool - - orig := str - - var output *stringBuilder - - for len(str) > 0 { - r, size = utf8.DecodeRuneInString(str) - r, needTr = tr.TranslateRune(r) - - if needTr && output == nil { - output = allocBuffer(orig, str) - } - - if r != utf8.RuneError && output != nil { - output.WriteRune(r) - } - - str = str[size:] - } - - // No character is translated. - if output == nil { - return orig - } - - return output.String() -} - -// TranslateRune return translated rune and true if r matches the from pattern. -// If r doesn't match the pattern, original r is returned and translated is false. -func (tr *Translator) TranslateRune(r rune) (result rune, translated bool) { - switch { - case tr.quickDict != nil: - if r <= unicode.MaxASCII { - result = tr.quickDict.Dict[r] - - if result != 0 { - translated = true - - if tr.mappedRune >= 0 { - result = tr.mappedRune - } - - break - } - } - - fallthrough - - case tr.runeMap != nil: - var ok bool - - if result, ok = tr.runeMap[r]; ok { - translated = true - - if tr.mappedRune >= 0 { - result = tr.mappedRune - } - - break - } - - fallthrough - - default: - var rrm *runeRangeMap - ranges := tr.ranges - - for i := len(ranges) - 1; i >= 0; i-- { - rrm = ranges[i] - - if rrm.FromLo <= r && r <= rrm.FromHi { - translated = true - - if tr.mappedRune >= 0 { - result = tr.mappedRune - break - } - - if rrm.ToLo < rrm.ToHi { - result = rrm.ToLo + r - rrm.FromLo - } else if rrm.ToLo > rrm.ToHi { - // ToHi can be smaller than ToLo if range is from higher to lower. - result = rrm.ToLo - r + rrm.FromLo - } else { - result = rrm.ToLo - } - - break - } - } - } - - if tr.reverted { - if !translated { - result = tr.mappedRune - } - - translated = !translated - } - - if !translated { - result = r - } - - return -} - -// HasPattern returns true if Translator has one pattern at least. -func (tr *Translator) HasPattern() bool { - return tr.hasPattern -} - -// Translate str with the characters defined in from replaced by characters defined in to. -// -// From and to are patterns representing a set of characters. Pattern is defined as following. -// -// Special characters: -// -// 1. '-' means a range of runes, e.g. -// "a-z" means all characters from 'a' to 'z' inclusive; -// "z-a" means all characters from 'z' to 'a' inclusive. -// 2. '^' as first character means a set of all runes excepted listed, e.g. -// "^a-z" means all characters except 'a' to 'z' inclusive. -// 3. '\' escapes special characters. -// -// Normal character represents itself, e.g. "abc" is a set including 'a', 'b' and 'c'. -// -// Translate will try to find a 1:1 mapping from from to to. -// If to is smaller than from, last rune in to will be used to map "out of range" characters in from. -// -// Note that '^' only works in the from pattern. It will be considered as a normal character in the to pattern. -// -// If the to pattern is an empty string, Translate works exactly the same as Delete. -// -// Samples: -// -// Translate("hello", "aeiou", "12345") => "h2ll4" -// Translate("hello", "a-z", "A-Z") => "HELLO" -// Translate("hello", "z-a", "a-z") => "svool" -// Translate("hello", "aeiou", "*") => "h*ll*" -// Translate("hello", "^l", "*") => "**ll*" -// Translate("hello ^ world", `\^lo`, "*") => "he*** * w*r*d" -func Translate(str, from, to string) string { - tr := NewTranslator(from, to) - return tr.Translate(str) -} - -// Delete runes in str matching the pattern. -// Pattern is defined in Translate function. -// -// Samples: -// -// Delete("hello", "aeiou") => "hll" -// Delete("hello", "a-k") => "llo" -// Delete("hello", "^a-k") => "he" -func Delete(str, pattern string) string { - tr := NewTranslator(pattern, "") - return tr.Translate(str) -} - -// Count how many runes in str match the pattern. -// Pattern is defined in Translate function. -// -// Samples: -// -// Count("hello", "aeiou") => 3 -// Count("hello", "a-k") => 3 -// Count("hello", "^a-k") => 2 -func Count(str, pattern string) int { - if pattern == "" || str == "" { - return 0 - } - - var r rune - var size int - var matched bool - - tr := NewTranslator(pattern, "") - cnt := 0 - - for len(str) > 0 { - r, size = utf8.DecodeRuneInString(str) - str = str[size:] - - if _, matched = tr.TranslateRune(r); matched { - cnt++ - } - } - - return cnt -} - -// Squeeze deletes adjacent repeated runes in str. -// If pattern is not empty, only runes matching the pattern will be squeezed. -// -// Samples: -// -// Squeeze("hello", "") => "helo" -// Squeeze("hello", "m-z") => "hello" -// Squeeze("hello world", " ") => "hello world" -func Squeeze(str, pattern string) string { - var last, r rune - var size int - var skipSqueeze, matched bool - var tr *Translator - var output *stringBuilder - - orig := str - last = -1 - - if len(pattern) > 0 { - tr = NewTranslator(pattern, "") - } - - for len(str) > 0 { - r, size = utf8.DecodeRuneInString(str) - - // Need to squeeze the str. - if last == r && !skipSqueeze { - if tr != nil { - if _, matched = tr.TranslateRune(r); !matched { - skipSqueeze = true - } - } - - if output == nil { - output = allocBuffer(orig, str) - } - - if skipSqueeze { - output.WriteRune(r) - } - } else { - if output != nil { - output.WriteRune(r) - } - - last = r - skipSqueeze = false - } - - str = str[size:] - } - - if output == nil { - return orig - } - - return output.String() -} |