From 921818bca208f0c70e85ec670074cb3905cbbc82 Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sat, 27 Aug 2016 01:32:30 +0100 Subject: Update dependencies --- vendor/gopkg.in/mgo.v2/internal/json/fold.go | 143 +++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 vendor/gopkg.in/mgo.v2/internal/json/fold.go (limited to 'vendor/gopkg.in/mgo.v2/internal/json/fold.go') diff --git a/vendor/gopkg.in/mgo.v2/internal/json/fold.go b/vendor/gopkg.in/mgo.v2/internal/json/fold.go new file mode 100644 index 0000000..9e17012 --- /dev/null +++ b/vendor/gopkg.in/mgo.v2/internal/json/fold.go @@ -0,0 +1,143 @@ +// 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 json + +import ( + "bytes" + "unicode/utf8" +) + +const ( + caseMask = ^byte(0x20) // Mask to ignore case in ASCII. + kelvin = '\u212a' + smallLongEss = '\u017f' +) + +// foldFunc returns one of four different case folding equivalence +// functions, from most general (and slow) to fastest: +// +// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8 +// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S') +// 3) asciiEqualFold, no special, but includes non-letters (including _) +// 4) simpleLetterEqualFold, no specials, no non-letters. +// +// The letters S and K are special because they map to 3 runes, not just 2: +// * S maps to s and to U+017F 'ſ' Latin small letter long s +// * k maps to K and to U+212A 'K' Kelvin sign +// See https://play.golang.org/p/tTxjOc0OGo +// +// The returned function is specialized for matching against s and +// should only be given s. It's not curried for performance reasons. +func foldFunc(s []byte) func(s, t []byte) bool { + nonLetter := false + special := false // special letter + for _, b := range s { + if b >= utf8.RuneSelf { + return bytes.EqualFold + } + upper := b & caseMask + if upper < 'A' || upper > 'Z' { + nonLetter = true + } else if upper == 'K' || upper == 'S' { + // See above for why these letters are special. + special = true + } + } + if special { + return equalFoldRight + } + if nonLetter { + return asciiEqualFold + } + return simpleLetterEqualFold +} + +// equalFoldRight is a specialization of bytes.EqualFold when s is +// known to be all ASCII (including punctuation), but contains an 's', +// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t. +// See comments on foldFunc. +func equalFoldRight(s, t []byte) bool { + for _, sb := range s { + if len(t) == 0 { + return false + } + tb := t[0] + if tb < utf8.RuneSelf { + if sb != tb { + sbUpper := sb & caseMask + if 'A' <= sbUpper && sbUpper <= 'Z' { + if sbUpper != tb&caseMask { + return false + } + } else { + return false + } + } + t = t[1:] + continue + } + // sb is ASCII and t is not. t must be either kelvin + // sign or long s; sb must be s, S, k, or K. + tr, size := utf8.DecodeRune(t) + switch sb { + case 's', 'S': + if tr != smallLongEss { + return false + } + case 'k', 'K': + if tr != kelvin { + return false + } + default: + return false + } + t = t[size:] + + } + if len(t) > 0 { + return false + } + return true +} + +// asciiEqualFold is a specialization of bytes.EqualFold for use when +// s is all ASCII (but may contain non-letters) and contains no +// special-folding letters. +// See comments on foldFunc. +func asciiEqualFold(s, t []byte) bool { + if len(s) != len(t) { + return false + } + for i, sb := range s { + tb := t[i] + if sb == tb { + continue + } + if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') { + if sb&caseMask != tb&caseMask { + return false + } + } else { + return false + } + } + return true +} + +// simpleLetterEqualFold is a specialization of bytes.EqualFold for +// use when s is all ASCII letters (no underscores, etc) and also +// doesn't contain 'k', 'K', 's', or 'S'. +// See comments on foldFunc. +func simpleLetterEqualFold(s, t []byte) bool { + if len(s) != len(t) { + return false + } + for i, b := range s { + if b&caseMask != t[i]&caseMask { + return false + } + } + return true +} -- cgit v1.2.3