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author | Péter Szilágyi <peterke@gmail.com> | 2016-02-11 22:16:52 +0800 |
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committer | Péter Szilágyi <peterke@gmail.com> | 2016-02-11 22:16:52 +0800 |
commit | b019f3ee29ce55c3d515ee8bafe0f4bb14221c0a (patch) | |
tree | 26e023be6c99a10e82a5a0ebadd1e42cefe9bd3c /Godeps/_workspace/src/golang.org/x/text/runes/runes.go | |
parent | b05e472c076d30035233d6a8b5fb3360b236e3ff (diff) | |
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Godeps: update all dependencies to latest code
Diffstat (limited to 'Godeps/_workspace/src/golang.org/x/text/runes/runes.go')
-rw-r--r-- | Godeps/_workspace/src/golang.org/x/text/runes/runes.go | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/golang.org/x/text/runes/runes.go b/Godeps/_workspace/src/golang.org/x/text/runes/runes.go new file mode 100644 index 000000000..291de656b --- /dev/null +++ b/Godeps/_workspace/src/golang.org/x/text/runes/runes.go @@ -0,0 +1,278 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package runes provide transforms for UTF-8 encoded text. +package runes + +import ( + "unicode" + "unicode/utf8" + + "golang.org/x/text/transform" +) + +// A Set is a collection of runes. +type Set interface { + // Contains returns true if r is contained in the set. + Contains(r rune) bool +} + +type setFunc func(rune) bool + +func (s setFunc) Contains(r rune) bool { + return s(r) +} + +// Note: using funcs here instead of wrapping types result in cleaner +// documentation and a smaller API. + +// In creates a Set with a Contains method that returns true for all runes in +// the given RangeTable. +func In(rt *unicode.RangeTable) Set { + return setFunc(func(r rune) bool { return unicode.Is(rt, r) }) +} + +// In creates a Set with a Contains method that returns true for all runes not +// in the given RangeTable. +func NotIn(rt *unicode.RangeTable) Set { + return setFunc(func(r rune) bool { return !unicode.Is(rt, r) }) +} + +// Predicate creates a Set with a Contains method that returns f(r). +func Predicate(f func(rune) bool) Set { + return setFunc(f) +} + +// Transformer implements the transform.Transformer interface. +type Transformer struct { + transform.Transformer +} + +// Bytes returns a new byte slice with the result of converting b using t. It +// calls Reset on t. It returns nil if any error was found. This can only happen +// if an error-producing Transformer is passed to If. +func (t Transformer) Bytes(b []byte) []byte { + b, _, err := transform.Bytes(t, b) + if err != nil { + return nil + } + return b +} + +// String returns a string with the result of converting s using t. It calls +// Reset on t. It returns the empty string if any error was found. This can only +// happen if an error-producing Transformer is passed to If. +func (t Transformer) String(s string) string { + s, _, err := transform.String(t, s) + if err != nil { + return "" + } + return s +} + +// TODO: +// - Copy: copying strings and bytes in whole-rune units. +// - Validation (maybe) +// - Well-formed-ness (maybe) + +const runeErrorString = string(utf8.RuneError) + +// Remove returns a Transformer that removes runes r for which s.Contains(r). +// Illegal input bytes are replaced by RuneError before being passed to f. +func Remove(s Set) Transformer { + if f, ok := s.(setFunc); ok { + // This little trick cuts the running time of BenchmarkRemove for sets + // created by Predicate roughly in half. + // TODO: special-case RangeTables as well. + return Transformer{remove(f)} + } + return Transformer{remove(s.Contains)} +} + +// TODO: remove transform.RemoveFunc. + +type remove func(r rune) bool + +func (remove) Reset() {} + +// Transform implements transform.Transformer. +func (t remove) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + for r, size := rune(0), 0; nSrc < len(src); { + if r = rune(src[nSrc]); r < utf8.RuneSelf { + size = 1 + } else { + r, size = utf8.DecodeRune(src[nSrc:]) + + if size == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src[nSrc:]) { + err = transform.ErrShortSrc + break + } + // We replace illegal bytes with RuneError. Not doing so might + // otherwise turn a sequence of invalid UTF-8 into valid UTF-8. + // The resulting byte sequence may subsequently contain runes + // for which t(r) is true that were passed unnoticed. + if !t(utf8.RuneError) { + if nDst+3 > len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst+0] = runeErrorString[0] + dst[nDst+1] = runeErrorString[1] + dst[nDst+2] = runeErrorString[2] + nDst += 3 + } + nSrc++ + continue + } + } + + if t(r) { + nSrc += size + continue + } + if nDst+size > len(dst) { + err = transform.ErrShortDst + break + } + for i := 0; i < size; i++ { + dst[nDst] = src[nSrc] + nDst++ + nSrc++ + } + } + return +} + +// Map returns a Transformer that maps the runes in the input using the given +// mapping. Illegal bytes in the input are converted to utf8.RuneError before +// being passed to the mapping func. +func Map(mapping func(rune) rune) Transformer { + return Transformer{mapper(mapping)} +} + +type mapper func(rune) rune + +func (mapper) Reset() {} + +// Transform implements transform.Transformer. +func (t mapper) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + var replacement rune + var b [utf8.UTFMax]byte + + for r, size := rune(0), 0; nSrc < len(src); { + if r = rune(src[nSrc]); r < utf8.RuneSelf { + if replacement = t(r); replacement < utf8.RuneSelf { + if nDst == len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst] = byte(replacement) + nDst++ + nSrc++ + continue + } + size = 1 + } else if r, size = utf8.DecodeRune(src[nSrc:]); size == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src[nSrc:]) { + err = transform.ErrShortSrc + break + } + + if replacement = t(utf8.RuneError); replacement == utf8.RuneError { + if nDst+3 > len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst+0] = runeErrorString[0] + dst[nDst+1] = runeErrorString[1] + dst[nDst+2] = runeErrorString[2] + nDst += 3 + nSrc++ + continue + } + } else if replacement = t(r); replacement == r { + if nDst+size > len(dst) { + err = transform.ErrShortDst + break + } + for i := 0; i < size; i++ { + dst[nDst] = src[nSrc] + nDst++ + nSrc++ + } + continue + } + + n := utf8.EncodeRune(b[:], replacement) + + if nDst+n > len(dst) { + err = transform.ErrShortDst + break + } + for i := 0; i < n; i++ { + dst[nDst] = b[i] + nDst++ + } + nSrc += size + } + return +} + +// ReplaceIllFormed returns a transformer that replaces all input bytes that are +// not part of a well-formed UTF-8 code sequence with utf8.RuneError. +func ReplaceIllFormed() Transformer { + return Transformer{&replaceIllFormed{}} +} + +type replaceIllFormed struct{ transform.NopResetter } + +func (t replaceIllFormed) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + for nSrc < len(src) { + r, size := utf8.DecodeRune(src[nSrc:]) + + // Look for an ASCII rune. + if r < utf8.RuneSelf { + if nDst == len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst] = byte(r) + nDst++ + nSrc++ + continue + } + + // Look for a valid non-ASCII rune. + if r != utf8.RuneError || size != 1 { + if size != copy(dst[nDst:], src[nSrc:nSrc+size]) { + err = transform.ErrShortDst + break + } + nDst += size + nSrc += size + continue + } + + // Look for short source data. + if !atEOF && !utf8.FullRune(src[nSrc:]) { + err = transform.ErrShortSrc + break + } + + // We have an invalid rune. + if nDst+3 > len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst+0] = runeErrorString[0] + dst[nDst+1] = runeErrorString[1] + dst[nDst+2] = runeErrorString[2] + nDst += 3 + nSrc++ + } + return nDst, nSrc, err +} |