1// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
2
3// Copyright 2016 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7package idna
8
9// appendMapping appends the mapping for the respective rune. isMapped must be
10// true. A mapping is a categorization of a rune as defined in UTS #46.
11func (c info) appendMapping(b []byte, s string) []byte {
12	index := int(c >> indexShift)
13	if c&xorBit == 0 {
14		s := mappings[index:]
15		return append(b, s[1:s[0]+1]...)
16	}
17	b = append(b, s...)
18	if c&inlineXOR == inlineXOR {
19		// TODO: support and handle two-byte inline masks
20		b[len(b)-1] ^= byte(index)
21	} else {
22		for p := len(b) - int(xorData[index]); p < len(b); p++ {
23			index++
24			b[p] ^= xorData[index]
25		}
26	}
27	return b
28}
29
30// Sparse block handling code.
31
32type valueRange struct {
33	value  uint16 // header: value:stride
34	lo, hi byte   // header: lo:n
35}
36
37type sparseBlocks struct {
38	values []valueRange
39	offset []uint16
40}
41
42var idnaSparse = sparseBlocks{
43	values: idnaSparseValues[:],
44	offset: idnaSparseOffset[:],
45}
46
47// Don't use newIdnaTrie to avoid unconditional linking in of the table.
48var trie = &idnaTrie{}
49
50// lookup determines the type of block n and looks up the value for b.
51// For n < t.cutoff, the block is a simple lookup table. Otherwise, the block
52// is a list of ranges with an accompanying value. Given a matching range r,
53// the value for b is by r.value + (b - r.lo) * stride.
54func (t *sparseBlocks) lookup(n uint32, b byte) uint16 {
55	offset := t.offset[n]
56	header := t.values[offset]
57	lo := offset + 1
58	hi := lo + uint16(header.lo)
59	for lo < hi {
60		m := lo + (hi-lo)/2
61		r := t.values[m]
62		if r.lo <= b && b <= r.hi {
63			return r.value + uint16(b-r.lo)*header.value
64		}
65		if b < r.lo {
66			hi = m
67		} else {
68			lo = m + 1
69		}
70	}
71	return 0
72}
73