| David K. Bainbridge | 215e024 | 2017-09-05 23:18:24 -0700 | [diff] [blame^] | 1 | // Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT. |
| 2 | |
| 3 | package idna |
| 4 | |
| 5 | // This file contains definitions for interpreting the trie value of the idna |
| 6 | // trie generated by "go run gen*.go". It is shared by both the generator |
| 7 | // program and the resultant package. Sharing is achieved by the generator |
| 8 | // copying gen_trieval.go to trieval.go and changing what's above this comment. |
| 9 | |
| 10 | // info holds information from the IDNA mapping table for a single rune. It is |
| 11 | // the value returned by a trie lookup. In most cases, all information fits in |
| 12 | // a 16-bit value. For mappings, this value may contain an index into a slice |
| 13 | // with the mapped string. Such mappings can consist of the actual mapped value |
| 14 | // or an XOR pattern to be applied to the bytes of the UTF8 encoding of the |
| 15 | // input rune. This technique is used by the cases packages and reduces the |
| 16 | // table size significantly. |
| 17 | // |
| 18 | // The per-rune values have the following format: |
| 19 | // |
| 20 | // if mapped { |
| 21 | // if inlinedXOR { |
| 22 | // 15..13 inline XOR marker |
| 23 | // 12..11 unused |
| 24 | // 10..3 inline XOR mask |
| 25 | // } else { |
| 26 | // 15..3 index into xor or mapping table |
| 27 | // } |
| 28 | // } else { |
| 29 | // 15..13 unused |
| 30 | // 12 modifier (including virama) |
| 31 | // 11 virama modifier |
| 32 | // 10..8 joining type |
| 33 | // 7..3 category type |
| 34 | // } |
| 35 | // 2 use xor pattern |
| 36 | // 1..0 mapped category |
| 37 | // |
| 38 | // See the definitions below for a more detailed description of the various |
| 39 | // bits. |
| 40 | type info uint16 |
| 41 | |
| 42 | const ( |
| 43 | catSmallMask = 0x3 |
| 44 | catBigMask = 0xF8 |
| 45 | indexShift = 3 |
| 46 | xorBit = 0x4 // interpret the index as an xor pattern |
| 47 | inlineXOR = 0xE000 // These bits are set if the XOR pattern is inlined. |
| 48 | |
| 49 | joinShift = 8 |
| 50 | joinMask = 0x07 |
| 51 | |
| 52 | viramaModifier = 0x0800 |
| 53 | modifier = 0x1000 |
| 54 | ) |
| 55 | |
| 56 | // A category corresponds to a category defined in the IDNA mapping table. |
| 57 | type category uint16 |
| 58 | |
| 59 | const ( |
| 60 | unknown category = 0 // not defined currently in unicode. |
| 61 | mapped category = 1 |
| 62 | disallowedSTD3Mapped category = 2 |
| 63 | deviation category = 3 |
| 64 | ) |
| 65 | |
| 66 | const ( |
| 67 | valid category = 0x08 |
| 68 | validNV8 category = 0x18 |
| 69 | validXV8 category = 0x28 |
| 70 | disallowed category = 0x40 |
| 71 | disallowedSTD3Valid category = 0x80 |
| 72 | ignored category = 0xC0 |
| 73 | ) |
| 74 | |
| 75 | // join types and additional rune information |
| 76 | const ( |
| 77 | joiningL = (iota + 1) |
| 78 | joiningD |
| 79 | joiningT |
| 80 | joiningR |
| 81 | |
| 82 | //the following types are derived during processing |
| 83 | joinZWJ |
| 84 | joinZWNJ |
| 85 | joinVirama |
| 86 | numJoinTypes |
| 87 | ) |
| 88 | |
| 89 | func (c info) isMapped() bool { |
| 90 | return c&0x3 != 0 |
| 91 | } |
| 92 | |
| 93 | func (c info) category() category { |
| 94 | small := c & catSmallMask |
| 95 | if small != 0 { |
| 96 | return category(small) |
| 97 | } |
| 98 | return category(c & catBigMask) |
| 99 | } |
| 100 | |
| 101 | func (c info) joinType() info { |
| 102 | if c.isMapped() { |
| 103 | return 0 |
| 104 | } |
| 105 | return (c >> joinShift) & joinMask |
| 106 | } |
| 107 | |
| 108 | func (c info) isModifier() bool { |
| 109 | return c&(modifier|catSmallMask) == modifier |
| 110 | } |
| 111 | |
| 112 | func (c info) isViramaModifier() bool { |
| 113 | return c&(viramaModifier|catSmallMask) == viramaModifier |
| 114 | } |