From 7b320119ba532fd409ec7dade7ad02011c309599 Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Wed, 18 Oct 2017 13:15:14 +0100 Subject: Update dependencies --- vendor/golang.org/x/text/internal/colltab/trie.go | 159 ++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 vendor/golang.org/x/text/internal/colltab/trie.go (limited to 'vendor/golang.org/x/text/internal/colltab/trie.go') diff --git a/vendor/golang.org/x/text/internal/colltab/trie.go b/vendor/golang.org/x/text/internal/colltab/trie.go new file mode 100644 index 0000000..a0eaa0d --- /dev/null +++ b/vendor/golang.org/x/text/internal/colltab/trie.go @@ -0,0 +1,159 @@ +// Copyright 2012 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. + +// The trie in this file is used to associate the first full character in an +// UTF-8 string to a collation element. All but the last byte in a UTF-8 byte +// sequence are used to lookup offsets in the index table to be used for the +// next byte. The last byte is used to index into a table of collation elements. +// For a full description, see go.text/collate/build/trie.go. + +package colltab + +const blockSize = 64 + +type Trie struct { + Index0 []uint16 // index for first byte (0xC0-0xFF) + Values0 []uint32 // index for first byte (0x00-0x7F) + Index []uint16 + Values []uint32 +} + +const ( + t1 = 0x00 // 0000 0000 + tx = 0x80 // 1000 0000 + t2 = 0xC0 // 1100 0000 + t3 = 0xE0 // 1110 0000 + t4 = 0xF0 // 1111 0000 + t5 = 0xF8 // 1111 1000 + t6 = 0xFC // 1111 1100 + te = 0xFE // 1111 1110 +) + +func (t *Trie) lookupValue(n uint16, b byte) Elem { + return Elem(t.Values[int(n)<<6+int(b)]) +} + +// lookup returns the trie value for the first UTF-8 encoding in s and +// the width in bytes of this encoding. The size will be 0 if s does not +// hold enough bytes to complete the encoding. len(s) must be greater than 0. +func (t *Trie) lookup(s []byte) (v Elem, sz int) { + c0 := s[0] + switch { + case c0 < tx: + return Elem(t.Values0[c0]), 1 + case c0 < t2: + return 0, 1 + case c0 < t3: + if len(s) < 2 { + return 0, 0 + } + i := t.Index0[c0] + c1 := s[1] + if c1 < tx || t2 <= c1 { + return 0, 1 + } + return t.lookupValue(i, c1), 2 + case c0 < t4: + if len(s) < 3 { + return 0, 0 + } + i := t.Index0[c0] + c1 := s[1] + if c1 < tx || t2 <= c1 { + return 0, 1 + } + o := int(i)<<6 + int(c1) + i = t.Index[o] + c2 := s[2] + if c2 < tx || t2 <= c2 { + return 0, 2 + } + return t.lookupValue(i, c2), 3 + case c0 < t5: + if len(s) < 4 { + return 0, 0 + } + i := t.Index0[c0] + c1 := s[1] + if c1 < tx || t2 <= c1 { + return 0, 1 + } + o := int(i)<<6 + int(c1) + i = t.Index[o] + c2 := s[2] + if c2 < tx || t2 <= c2 { + return 0, 2 + } + o = int(i)<<6 + int(c2) + i = t.Index[o] + c3 := s[3] + if c3 < tx || t2 <= c3 { + return 0, 3 + } + return t.lookupValue(i, c3), 4 + } + // Illegal rune + return 0, 1 +} + +// The body of lookupString is a verbatim copy of that of lookup. +func (t *Trie) lookupString(s string) (v Elem, sz int) { + c0 := s[0] + switch { + case c0 < tx: + return Elem(t.Values0[c0]), 1 + case c0 < t2: + return 0, 1 + case c0 < t3: + if len(s) < 2 { + return 0, 0 + } + i := t.Index0[c0] + c1 := s[1] + if c1 < tx || t2 <= c1 { + return 0, 1 + } + return t.lookupValue(i, c1), 2 + case c0 < t4: + if len(s) < 3 { + return 0, 0 + } + i := t.Index0[c0] + c1 := s[1] + if c1 < tx || t2 <= c1 { + return 0, 1 + } + o := int(i)<<6 + int(c1) + i = t.Index[o] + c2 := s[2] + if c2 < tx || t2 <= c2 { + return 0, 2 + } + return t.lookupValue(i, c2), 3 + case c0 < t5: + if len(s) < 4 { + return 0, 0 + } + i := t.Index0[c0] + c1 := s[1] + if c1 < tx || t2 <= c1 { + return 0, 1 + } + o := int(i)<<6 + int(c1) + i = t.Index[o] + c2 := s[2] + if c2 < tx || t2 <= c2 { + return 0, 2 + } + o = int(i)<<6 + int(c2) + i = t.Index[o] + c3 := s[3] + if c3 < tx || t2 <= c3 { + return 0, 3 + } + return t.lookupValue(i, c3), 4 + } + // Illegal rune + return 0, 1 +} -- cgit v1.2.3