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-rw-r--r--vendor/golang.org/x/text/encoding/unicode/override.go82
-rw-r--r--vendor/golang.org/x/text/encoding/unicode/unicode.go434
2 files changed, 516 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/encoding/unicode/override.go b/vendor/golang.org/x/text/encoding/unicode/override.go
new file mode 100644
index 0000000..35d62fc
--- /dev/null
+++ b/vendor/golang.org/x/text/encoding/unicode/override.go
@@ -0,0 +1,82 @@
+// Copyright 2015 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 unicode
+
+import (
+ "golang.org/x/text/transform"
+)
+
+// BOMOverride returns a new decoder transformer that is identical to fallback,
+// except that the presence of a Byte Order Mark at the start of the input
+// causes it to switch to the corresponding Unicode decoding. It will only
+// consider BOMs for UTF-8, UTF-16BE, and UTF-16LE.
+//
+// This differs from using ExpectBOM by allowing a BOM to switch to UTF-8, not
+// just UTF-16 variants, and allowing falling back to any encoding scheme.
+//
+// This technique is recommended by the W3C for use in HTML 5: "For
+// compatibility with deployed content, the byte order mark (also known as BOM)
+// is considered more authoritative than anything else."
+// http://www.w3.org/TR/encoding/#specification-hooks
+//
+// Using BOMOverride is mostly intended for use cases where the first characters
+// of a fallback encoding are known to not be a BOM, for example, for valid HTML
+// and most encodings.
+func BOMOverride(fallback transform.Transformer) transform.Transformer {
+ // TODO: possibly allow a variadic argument of unicode encodings to allow
+ // specifying details of which fallbacks are supported as well as
+ // specifying the details of the implementations. This would also allow for
+ // support for UTF-32, which should not be supported by default.
+ return &bomOverride{fallback: fallback}
+}
+
+type bomOverride struct {
+ fallback transform.Transformer
+ current transform.Transformer
+}
+
+func (d *bomOverride) Reset() {
+ d.current = nil
+ d.fallback.Reset()
+}
+
+var (
+ // TODO: we could use decode functions here, instead of allocating a new
+ // decoder on every NewDecoder as IgnoreBOM decoders can be stateless.
+ utf16le = UTF16(LittleEndian, IgnoreBOM)
+ utf16be = UTF16(BigEndian, IgnoreBOM)
+)
+
+const utf8BOM = "\ufeff"
+
+func (d *bomOverride) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ if d.current != nil {
+ return d.current.Transform(dst, src, atEOF)
+ }
+ if len(src) < 3 && !atEOF {
+ return 0, 0, transform.ErrShortSrc
+ }
+ d.current = d.fallback
+ bomSize := 0
+ if len(src) >= 2 {
+ if src[0] == 0xFF && src[1] == 0xFE {
+ d.current = utf16le.NewDecoder()
+ bomSize = 2
+ } else if src[0] == 0xFE && src[1] == 0xFF {
+ d.current = utf16be.NewDecoder()
+ bomSize = 2
+ } else if len(src) >= 3 &&
+ src[0] == utf8BOM[0] &&
+ src[1] == utf8BOM[1] &&
+ src[2] == utf8BOM[2] {
+ d.current = transform.Nop
+ bomSize = 3
+ }
+ }
+ if bomSize < len(src) {
+ nDst, nSrc, err = d.current.Transform(dst, src[bomSize:], atEOF)
+ }
+ return nDst, nSrc + bomSize, err
+}
diff --git a/vendor/golang.org/x/text/encoding/unicode/unicode.go b/vendor/golang.org/x/text/encoding/unicode/unicode.go
new file mode 100644
index 0000000..579cadf
--- /dev/null
+++ b/vendor/golang.org/x/text/encoding/unicode/unicode.go
@@ -0,0 +1,434 @@
+// Copyright 2013 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 unicode provides Unicode encodings such as UTF-16.
+package unicode // import "golang.org/x/text/encoding/unicode"
+
+import (
+ "errors"
+ "unicode/utf16"
+ "unicode/utf8"
+
+ "golang.org/x/text/encoding"
+ "golang.org/x/text/encoding/internal"
+ "golang.org/x/text/encoding/internal/identifier"
+ "golang.org/x/text/internal/utf8internal"
+ "golang.org/x/text/runes"
+ "golang.org/x/text/transform"
+)
+
+// TODO: I think the Transformers really should return errors on unmatched
+// surrogate pairs and odd numbers of bytes. This is not required by RFC 2781,
+// which leaves it open, but is suggested by WhatWG. It will allow for all error
+// modes as defined by WhatWG: fatal, HTML and Replacement. This would require
+// the introduction of some kind of error type for conveying the erroneous code
+// point.
+
+// UTF8 is the UTF-8 encoding.
+var UTF8 encoding.Encoding = utf8enc
+
+var utf8enc = &internal.Encoding{
+ &internal.SimpleEncoding{utf8Decoder{}, runes.ReplaceIllFormed()},
+ "UTF-8",
+ identifier.UTF8,
+}
+
+type utf8Decoder struct{ transform.NopResetter }
+
+func (utf8Decoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ var pSrc int // point from which to start copy in src
+ var accept utf8internal.AcceptRange
+
+ // The decoder can only make the input larger, not smaller.
+ n := len(src)
+ if len(dst) < n {
+ err = transform.ErrShortDst
+ n = len(dst)
+ atEOF = false
+ }
+ for nSrc < n {
+ c := src[nSrc]
+ if c < utf8.RuneSelf {
+ nSrc++
+ continue
+ }
+ first := utf8internal.First[c]
+ size := int(first & utf8internal.SizeMask)
+ if first == utf8internal.FirstInvalid {
+ goto handleInvalid // invalid starter byte
+ }
+ accept = utf8internal.AcceptRanges[first>>utf8internal.AcceptShift]
+ if nSrc+size > n {
+ if !atEOF {
+ // We may stop earlier than necessary here if the short sequence
+ // has invalid bytes. Not checking for this simplifies the code
+ // and may avoid duplicate computations in certain conditions.
+ if err == nil {
+ err = transform.ErrShortSrc
+ }
+ break
+ }
+ // Determine the maximal subpart of an ill-formed subsequence.
+ switch {
+ case nSrc+1 >= n || src[nSrc+1] < accept.Lo || accept.Hi < src[nSrc+1]:
+ size = 1
+ case nSrc+2 >= n || src[nSrc+2] < utf8internal.LoCB || utf8internal.HiCB < src[nSrc+2]:
+ size = 2
+ default:
+ size = 3 // As we are short, the maximum is 3.
+ }
+ goto handleInvalid
+ }
+ if c = src[nSrc+1]; c < accept.Lo || accept.Hi < c {
+ size = 1
+ goto handleInvalid // invalid continuation byte
+ } else if size == 2 {
+ } else if c = src[nSrc+2]; c < utf8internal.LoCB || utf8internal.HiCB < c {
+ size = 2
+ goto handleInvalid // invalid continuation byte
+ } else if size == 3 {
+ } else if c = src[nSrc+3]; c < utf8internal.LoCB || utf8internal.HiCB < c {
+ size = 3
+ goto handleInvalid // invalid continuation byte
+ }
+ nSrc += size
+ continue
+
+ handleInvalid:
+ // Copy the scanned input so far.
+ nDst += copy(dst[nDst:], src[pSrc:nSrc])
+
+ // Append RuneError to the destination.
+ const runeError = "\ufffd"
+ if nDst+len(runeError) > len(dst) {
+ return nDst, nSrc, transform.ErrShortDst
+ }
+ nDst += copy(dst[nDst:], runeError)
+
+ // Skip the maximal subpart of an ill-formed subsequence according to
+ // the W3C standard way instead of the Go way. This Transform is
+ // probably the only place in the text repo where it is warranted.
+ nSrc += size
+ pSrc = nSrc
+
+ // Recompute the maximum source length.
+ if sz := len(dst) - nDst; sz < len(src)-nSrc {
+ err = transform.ErrShortDst
+ n = nSrc + sz
+ atEOF = false
+ }
+ }
+ return nDst + copy(dst[nDst:], src[pSrc:nSrc]), nSrc, err
+}
+
+// UTF16 returns a UTF-16 Encoding for the given default endianness and byte
+// order mark (BOM) policy.
+//
+// When decoding from UTF-16 to UTF-8, if the BOMPolicy is IgnoreBOM then
+// neither BOMs U+FEFF nor noncharacters U+FFFE in the input stream will affect
+// the endianness used for decoding, and will instead be output as their
+// standard UTF-8 encodings: "\xef\xbb\xbf" and "\xef\xbf\xbe". If the BOMPolicy
+// is UseBOM or ExpectBOM a staring BOM is not written to the UTF-8 output.
+// Instead, it overrides the default endianness e for the remainder of the
+// transformation. Any subsequent BOMs U+FEFF or noncharacters U+FFFE will not
+// affect the endianness used, and will instead be output as their standard
+// UTF-8 encodings. For UseBOM, if there is no starting BOM, it will proceed
+// with the default Endianness. For ExpectBOM, in that case, the transformation
+// will return early with an ErrMissingBOM error.
+//
+// When encoding from UTF-8 to UTF-16, a BOM will be inserted at the start of
+// the output if the BOMPolicy is UseBOM or ExpectBOM. Otherwise, a BOM will not
+// be inserted. The UTF-8 input does not need to contain a BOM.
+//
+// There is no concept of a 'native' endianness. If the UTF-16 data is produced
+// and consumed in a greater context that implies a certain endianness, use
+// IgnoreBOM. Otherwise, use ExpectBOM and always produce and consume a BOM.
+//
+// In the language of http://www.unicode.org/faq/utf_bom.html#bom10, IgnoreBOM
+// corresponds to "Where the precise type of the data stream is known... the
+// BOM should not be used" and ExpectBOM corresponds to "A particular
+// protocol... may require use of the BOM".
+func UTF16(e Endianness, b BOMPolicy) encoding.Encoding {
+ return utf16Encoding{config{e, b}, mibValue[e][b&bomMask]}
+}
+
+// mibValue maps Endianness and BOMPolicy settings to MIB constants. Note that
+// some configurations map to the same MIB identifier. RFC 2781 has requirements
+// and recommendations. Some of the "configurations" are merely recommendations,
+// so multiple configurations could match.
+var mibValue = map[Endianness][numBOMValues]identifier.MIB{
+ BigEndian: [numBOMValues]identifier.MIB{
+ IgnoreBOM: identifier.UTF16BE,
+ UseBOM: identifier.UTF16, // BigEnding default is preferred by RFC 2781.
+ // TODO: acceptBOM | strictBOM would map to UTF16BE as well.
+ },
+ LittleEndian: [numBOMValues]identifier.MIB{
+ IgnoreBOM: identifier.UTF16LE,
+ UseBOM: identifier.UTF16, // LittleEndian default is allowed and preferred on Windows.
+ // TODO: acceptBOM | strictBOM would map to UTF16LE as well.
+ },
+ // ExpectBOM is not widely used and has no valid MIB identifier.
+}
+
+// All lists a configuration for each IANA-defined UTF-16 variant.
+var All = []encoding.Encoding{
+ UTF8,
+ UTF16(BigEndian, UseBOM),
+ UTF16(BigEndian, IgnoreBOM),
+ UTF16(LittleEndian, IgnoreBOM),
+}
+
+// BOMPolicy is a UTF-16 encoding's byte order mark policy.
+type BOMPolicy uint8
+
+const (
+ writeBOM BOMPolicy = 0x01
+ acceptBOM BOMPolicy = 0x02
+ requireBOM BOMPolicy = 0x04
+ bomMask BOMPolicy = 0x07
+
+ // HACK: numBOMValues == 8 triggers a bug in the 1.4 compiler (cannot have a
+ // map of an array of length 8 of a type that is also used as a key or value
+ // in another map). See golang.org/issue/11354.
+ // TODO: consider changing this value back to 8 if the use of 1.4.* has
+ // been minimized.
+ numBOMValues = 8 + 1
+
+ // IgnoreBOM means to ignore any byte order marks.
+ IgnoreBOM BOMPolicy = 0
+ // Common and RFC 2781-compliant interpretation for UTF-16BE/LE.
+
+ // UseBOM means that the UTF-16 form may start with a byte order mark, which
+ // will be used to override the default encoding.
+ UseBOM BOMPolicy = writeBOM | acceptBOM
+ // Common and RFC 2781-compliant interpretation for UTF-16.
+
+ // ExpectBOM means that the UTF-16 form must start with a byte order mark,
+ // which will be used to override the default encoding.
+ ExpectBOM BOMPolicy = writeBOM | acceptBOM | requireBOM
+ // Used in Java as Unicode (not to be confused with Java's UTF-16) and
+ // ICU's UTF-16,version=1. Not compliant with RFC 2781.
+
+ // TODO (maybe): strictBOM: BOM must match Endianness. This would allow:
+ // - UTF-16(B|L)E,version=1: writeBOM | acceptBOM | requireBOM | strictBOM
+ // (UnicodeBig and UnicodeLittle in Java)
+ // - RFC 2781-compliant, but less common interpretation for UTF-16(B|L)E:
+ // acceptBOM | strictBOM (e.g. assigned to CheckBOM).
+ // This addition would be consistent with supporting ExpectBOM.
+)
+
+// Endianness is a UTF-16 encoding's default endianness.
+type Endianness bool
+
+const (
+ // BigEndian is UTF-16BE.
+ BigEndian Endianness = false
+ // LittleEndian is UTF-16LE.
+ LittleEndian Endianness = true
+)
+
+// ErrMissingBOM means that decoding UTF-16 input with ExpectBOM did not find a
+// starting byte order mark.
+var ErrMissingBOM = errors.New("encoding: missing byte order mark")
+
+type utf16Encoding struct {
+ config
+ mib identifier.MIB
+}
+
+type config struct {
+ endianness Endianness
+ bomPolicy BOMPolicy
+}
+
+func (u utf16Encoding) NewDecoder() *encoding.Decoder {
+ return &encoding.Decoder{Transformer: &utf16Decoder{
+ initial: u.config,
+ current: u.config,
+ }}
+}
+
+func (u utf16Encoding) NewEncoder() *encoding.Encoder {
+ return &encoding.Encoder{Transformer: &utf16Encoder{
+ endianness: u.endianness,
+ initialBOMPolicy: u.bomPolicy,
+ currentBOMPolicy: u.bomPolicy,
+ }}
+}
+
+func (u utf16Encoding) ID() (mib identifier.MIB, other string) {
+ return u.mib, ""
+}
+
+func (u utf16Encoding) String() string {
+ e, b := "B", ""
+ if u.endianness == LittleEndian {
+ e = "L"
+ }
+ switch u.bomPolicy {
+ case ExpectBOM:
+ b = "Expect"
+ case UseBOM:
+ b = "Use"
+ case IgnoreBOM:
+ b = "Ignore"
+ }
+ return "UTF-16" + e + "E (" + b + " BOM)"
+}
+
+type utf16Decoder struct {
+ initial config
+ current config
+}
+
+func (u *utf16Decoder) Reset() {
+ u.current = u.initial
+}
+
+func (u *utf16Decoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ if len(src) == 0 {
+ if atEOF && u.current.bomPolicy&requireBOM != 0 {
+ return 0, 0, ErrMissingBOM
+ }
+ return 0, 0, nil
+ }
+ if u.current.bomPolicy&acceptBOM != 0 {
+ if len(src) < 2 {
+ return 0, 0, transform.ErrShortSrc
+ }
+ switch {
+ case src[0] == 0xfe && src[1] == 0xff:
+ u.current.endianness = BigEndian
+ nSrc = 2
+ case src[0] == 0xff && src[1] == 0xfe:
+ u.current.endianness = LittleEndian
+ nSrc = 2
+ default:
+ if u.current.bomPolicy&requireBOM != 0 {
+ return 0, 0, ErrMissingBOM
+ }
+ }
+ u.current.bomPolicy = IgnoreBOM
+ }
+
+ var r rune
+ var dSize, sSize int
+ for nSrc < len(src) {
+ if nSrc+1 < len(src) {
+ x := uint16(src[nSrc+0])<<8 | uint16(src[nSrc+1])
+ if u.current.endianness == LittleEndian {
+ x = x>>8 | x<<8
+ }
+ r, sSize = rune(x), 2
+ if utf16.IsSurrogate(r) {
+ if nSrc+3 < len(src) {
+ x = uint16(src[nSrc+2])<<8 | uint16(src[nSrc+3])
+ if u.current.endianness == LittleEndian {
+ x = x>>8 | x<<8
+ }
+ // Save for next iteration if it is not a high surrogate.
+ if isHighSurrogate(rune(x)) {
+ r, sSize = utf16.DecodeRune(r, rune(x)), 4
+ }
+ } else if !atEOF {
+ err = transform.ErrShortSrc
+ break
+ }
+ }
+ if dSize = utf8.RuneLen(r); dSize < 0 {
+ r, dSize = utf8.RuneError, 3
+ }
+ } else if atEOF {
+ // Single trailing byte.
+ r, dSize, sSize = utf8.RuneError, 3, 1
+ } else {
+ err = transform.ErrShortSrc
+ break
+ }
+ if nDst+dSize > len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ nDst += utf8.EncodeRune(dst[nDst:], r)
+ nSrc += sSize
+ }
+ return nDst, nSrc, err
+}
+
+func isHighSurrogate(r rune) bool {
+ return 0xDC00 <= r && r <= 0xDFFF
+}
+
+type utf16Encoder struct {
+ endianness Endianness
+ initialBOMPolicy BOMPolicy
+ currentBOMPolicy BOMPolicy
+}
+
+func (u *utf16Encoder) Reset() {
+ u.currentBOMPolicy = u.initialBOMPolicy
+}
+
+func (u *utf16Encoder) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ if u.currentBOMPolicy&writeBOM != 0 {
+ if len(dst) < 2 {
+ return 0, 0, transform.ErrShortDst
+ }
+ dst[0], dst[1] = 0xfe, 0xff
+ u.currentBOMPolicy = IgnoreBOM
+ nDst = 2
+ }
+
+ r, size := rune(0), 0
+ for nSrc < len(src) {
+ r = rune(src[nSrc])
+
+ // Decode a 1-byte rune.
+ if r < utf8.RuneSelf {
+ size = 1
+
+ } else {
+ // Decode a multi-byte rune.
+ r, size = utf8.DecodeRune(src[nSrc:])
+ if size == 1 {
+ // All valid runes of size 1 (those below utf8.RuneSelf) were
+ // handled above. We have invalid UTF-8 or we haven't seen the
+ // full character yet.
+ if !atEOF && !utf8.FullRune(src[nSrc:]) {
+ err = transform.ErrShortSrc
+ break
+ }
+ }
+ }
+
+ if r <= 0xffff {
+ if nDst+2 > len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ dst[nDst+0] = uint8(r >> 8)
+ dst[nDst+1] = uint8(r)
+ nDst += 2
+ } else {
+ if nDst+4 > len(dst) {
+ err = transform.ErrShortDst
+ break
+ }
+ r1, r2 := utf16.EncodeRune(r)
+ dst[nDst+0] = uint8(r1 >> 8)
+ dst[nDst+1] = uint8(r1)
+ dst[nDst+2] = uint8(r2 >> 8)
+ dst[nDst+3] = uint8(r2)
+ nDst += 4
+ }
+ nSrc += size
+ }
+
+ if u.endianness == LittleEndian {
+ for i := 0; i < nDst; i += 2 {
+ dst[i], dst[i+1] = dst[i+1], dst[i]
+ }
+ }
+ return nDst, nSrc, err
+}