summaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/text/runes/runes.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/text/runes/runes.go')
-rw-r--r--vendor/golang.org/x/text/runes/runes.go355
1 files changed, 355 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/runes/runes.go b/vendor/golang.org/x/text/runes/runes.go
new file mode 100644
index 0000000..7193369
--- /dev/null
+++ b/vendor/golang.org/x/text/runes/runes.go
@@ -0,0 +1,355 @@
+// 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 "golang.org/x/text/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 {
+ t transform.SpanningTransformer
+}
+
+func (t Transformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ return t.t.Transform(dst, src, atEOF)
+}
+
+func (t Transformer) Span(b []byte, atEOF bool) (n int, err error) {
+ return t.t.Span(b, atEOF)
+}
+
+func (t Transformer) Reset() { t.t.Reset() }
+
+// 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() {}
+
+// Span implements transform.Spanner.
+func (t remove) Span(src []byte, atEOF bool) (n int, err error) {
+ for r, size := rune(0), 0; n < len(src); {
+ if r = rune(src[n]); r < utf8.RuneSelf {
+ size = 1
+ } else if r, size = utf8.DecodeRune(src[n:]); size == 1 {
+ // Invalid rune.
+ if !atEOF && !utf8.FullRune(src[n:]) {
+ err = transform.ErrShortSrc
+ } else {
+ err = transform.ErrEndOfSpan
+ }
+ break
+ }
+ if t(r) {
+ err = transform.ErrEndOfSpan
+ break
+ }
+ n += size
+ }
+ return
+}
+
+// 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 if r, size = utf8.DecodeRune(src[nSrc:]); 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() {}
+
+// Span implements transform.Spanner.
+func (t mapper) Span(src []byte, atEOF bool) (n int, err error) {
+ for r, size := rune(0), 0; n < len(src); n += size {
+ if r = rune(src[n]); r < utf8.RuneSelf {
+ size = 1
+ } else if r, size = utf8.DecodeRune(src[n:]); size == 1 {
+ // Invalid rune.
+ if !atEOF && !utf8.FullRune(src[n:]) {
+ err = transform.ErrShortSrc
+ } else {
+ err = transform.ErrEndOfSpan
+ }
+ break
+ }
+ if t(r) != r {
+ err = transform.ErrEndOfSpan
+ break
+ }
+ }
+ return n, err
+}
+
+// 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) Span(src []byte, atEOF bool) (n int, err error) {
+ for n < len(src) {
+ // ASCII fast path.
+ if src[n] < utf8.RuneSelf {
+ n++
+ continue
+ }
+
+ r, size := utf8.DecodeRune(src[n:])
+
+ // Look for a valid non-ASCII rune.
+ if r != utf8.RuneError || size != 1 {
+ n += size
+ continue
+ }
+
+ // Look for short source data.
+ if !atEOF && !utf8.FullRune(src[n:]) {
+ err = transform.ErrShortSrc
+ break
+ }
+
+ // We have an invalid rune.
+ err = transform.ErrEndOfSpan
+ break
+ }
+ return n, err
+}
+
+func (t replaceIllFormed) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ for nSrc < len(src) {
+ // ASCII fast path.
+ if r := src[nSrc]; r < utf8.RuneSelf {
+ if nDst == len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ dst[nDst] = r
+ nDst++
+ nSrc++
+ continue
+ }
+
+ // Look for a valid non-ASCII rune.
+ if _, size := utf8.DecodeRune(src[nSrc:]); 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
+}