From 30802e07b2d84fbc213b490d3402707dffe60096 Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Mon, 10 Apr 2017 21:18:42 +0100 Subject: update dependencies --- vendor/golang.org/x/text/unicode/bidi/prop.go | 206 ++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 vendor/golang.org/x/text/unicode/bidi/prop.go (limited to 'vendor/golang.org/x/text/unicode/bidi/prop.go') diff --git a/vendor/golang.org/x/text/unicode/bidi/prop.go b/vendor/golang.org/x/text/unicode/bidi/prop.go new file mode 100644 index 0000000..7c9484e --- /dev/null +++ b/vendor/golang.org/x/text/unicode/bidi/prop.go @@ -0,0 +1,206 @@ +// Copyright 2016 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 bidi + +import "unicode/utf8" + +// Properties provides access to BiDi properties of runes. +type Properties struct { + entry uint8 + last uint8 +} + +var trie = newBidiTrie(0) + +// TODO: using this for bidirule reduces the running time by about 5%. Consider +// if this is worth exposing or if we can find a way to speed up the Class +// method. +// +// // CompactClass is like Class, but maps all of the BiDi control classes +// // (LRO, RLO, LRE, RLE, PDF, LRI, RLI, FSI, PDI) to the class Control. +// func (p Properties) CompactClass() Class { +// return Class(p.entry & 0x0F) +// } + +// Class returns the Bidi class for p. +func (p Properties) Class() Class { + c := Class(p.entry & 0x0F) + if c == Control { + c = controlByteToClass[p.last&0xF] + } + return c +} + +// IsBracket reports whether the rune is a bracket. +func (p Properties) IsBracket() bool { return p.entry&0xF0 != 0 } + +// IsOpeningBracket reports whether the rune is an opening bracket. +// IsBracket must return true. +func (p Properties) IsOpeningBracket() bool { return p.entry&openMask != 0 } + +// TODO: find a better API and expose. +func (p Properties) reverseBracket(r rune) rune { + return xorMasks[p.entry>>xorMaskShift] ^ r +} + +var controlByteToClass = [16]Class{ + 0xD: LRO, // U+202D LeftToRightOverride, + 0xE: RLO, // U+202E RightToLeftOverride, + 0xA: LRE, // U+202A LeftToRightEmbedding, + 0xB: RLE, // U+202B RightToLeftEmbedding, + 0xC: PDF, // U+202C PopDirectionalFormat, + 0x6: LRI, // U+2066 LeftToRightIsolate, + 0x7: RLI, // U+2067 RightToLeftIsolate, + 0x8: FSI, // U+2068 FirstStrongIsolate, + 0x9: PDI, // U+2069 PopDirectionalIsolate, +} + +// LookupRune returns properties for r. +func LookupRune(r rune) (p Properties, size int) { + var buf [4]byte + n := utf8.EncodeRune(buf[:], r) + return Lookup(buf[:n]) +} + +// TODO: these lookup methods are based on the generated trie code. The returned +// sizes have slightly different semantics from the generated code, in that it +// always returns size==1 for an illegal UTF-8 byte (instead of the length +// of the maximum invalid subsequence). Most Transformers, like unicode/norm, +// leave invalid UTF-8 untouched, in which case it has performance benefits to +// do so (without changing the semantics). Bidi requires the semantics used here +// for the bidirule implementation to be compatible with the Go semantics. +// They ultimately should perhaps be adopted by all trie implementations, for +// convenience sake. +// This unrolled code also boosts performance of the secure/bidirule package by +// about 30%. +// So, to remove this code: +// - add option to trie generator to define return type. +// - always return 1 byte size for ill-formed UTF-8 runes. + +// Lookup returns properties for the first rune in s and the width in bytes of +// its encoding. The size will be 0 if s does not hold enough bytes to complete +// the encoding. +func Lookup(s []byte) (p Properties, sz int) { + c0 := s[0] + switch { + case c0 < 0x80: // is ASCII + return Properties{entry: bidiValues[c0]}, 1 + case c0 < 0xC2: + return Properties{}, 1 + case c0 < 0xE0: // 2-byte UTF-8 + if len(s) < 2 { + return Properties{}, 0 + } + i := bidiIndex[c0] + c1 := s[1] + if c1 < 0x80 || 0xC0 <= c1 { + return Properties{}, 1 + } + return Properties{entry: trie.lookupValue(uint32(i), c1)}, 2 + case c0 < 0xF0: // 3-byte UTF-8 + if len(s) < 3 { + return Properties{}, 0 + } + i := bidiIndex[c0] + c1 := s[1] + if c1 < 0x80 || 0xC0 <= c1 { + return Properties{}, 1 + } + o := uint32(i)<<6 + uint32(c1) + i = bidiIndex[o] + c2 := s[2] + if c2 < 0x80 || 0xC0 <= c2 { + return Properties{}, 1 + } + return Properties{entry: trie.lookupValue(uint32(i), c2), last: c2}, 3 + case c0 < 0xF8: // 4-byte UTF-8 + if len(s) < 4 { + return Properties{}, 0 + } + i := bidiIndex[c0] + c1 := s[1] + if c1 < 0x80 || 0xC0 <= c1 { + return Properties{}, 1 + } + o := uint32(i)<<6 + uint32(c1) + i = bidiIndex[o] + c2 := s[2] + if c2 < 0x80 || 0xC0 <= c2 { + return Properties{}, 1 + } + o = uint32(i)<<6 + uint32(c2) + i = bidiIndex[o] + c3 := s[3] + if c3 < 0x80 || 0xC0 <= c3 { + return Properties{}, 1 + } + return Properties{entry: trie.lookupValue(uint32(i), c3)}, 4 + } + // Illegal rune + return Properties{}, 1 +} + +// LookupString returns properties for the first rune in s and the width in +// bytes of its encoding. The size will be 0 if s does not hold enough bytes to +// complete the encoding. +func LookupString(s string) (p Properties, sz int) { + c0 := s[0] + switch { + case c0 < 0x80: // is ASCII + return Properties{entry: bidiValues[c0]}, 1 + case c0 < 0xC2: + return Properties{}, 1 + case c0 < 0xE0: // 2-byte UTF-8 + if len(s) < 2 { + return Properties{}, 0 + } + i := bidiIndex[c0] + c1 := s[1] + if c1 < 0x80 || 0xC0 <= c1 { + return Properties{}, 1 + } + return Properties{entry: trie.lookupValue(uint32(i), c1)}, 2 + case c0 < 0xF0: // 3-byte UTF-8 + if len(s) < 3 { + return Properties{}, 0 + } + i := bidiIndex[c0] + c1 := s[1] + if c1 < 0x80 || 0xC0 <= c1 { + return Properties{}, 1 + } + o := uint32(i)<<6 + uint32(c1) + i = bidiIndex[o] + c2 := s[2] + if c2 < 0x80 || 0xC0 <= c2 { + return Properties{}, 1 + } + return Properties{entry: trie.lookupValue(uint32(i), c2), last: c2}, 3 + case c0 < 0xF8: // 4-byte UTF-8 + if len(s) < 4 { + return Properties{}, 0 + } + i := bidiIndex[c0] + c1 := s[1] + if c1 < 0x80 || 0xC0 <= c1 { + return Properties{}, 1 + } + o := uint32(i)<<6 + uint32(c1) + i = bidiIndex[o] + c2 := s[2] + if c2 < 0x80 || 0xC0 <= c2 { + return Properties{}, 1 + } + o = uint32(i)<<6 + uint32(c2) + i = bidiIndex[o] + c3 := s[3] + if c3 < 0x80 || 0xC0 <= c3 { + return Properties{}, 1 + } + return Properties{entry: trie.lookupValue(uint32(i), c3)}, 4 + } + // Illegal rune + return Properties{}, 1 +} -- cgit v1.2.3