comparison Implab/Formats/JSON/JSONGrammar.cs @ 190:1c2a16d071a7 v2

Слияние с ref20160224
author cin
date Fri, 22 Apr 2016 13:08:08 +0300
parents 4f82e0f161c3
children
comparison
equal deleted inserted replaced
161:2a8466f0cb8a 190:1c2a16d071a7
1 using System.Linq;
2 using Implab.Automaton.RegularExpressions;
3 using System;
4 using Implab.Automaton;
5 using Implab.Components;
6
7 namespace Implab.Formats.JSON {
8 class JSONGrammar : Grammar<char> {
9 public enum TokenType {
10 None,
11 BeginObject,
12 EndObject,
13 BeginArray,
14 EndArray,
15 String,
16 Number,
17 Literal,
18 NameSeparator,
19 ValueSeparator,
20 Whitespace,
21
22 StringBound,
23 EscapedChar,
24 UnescapedChar,
25 EscapedUnicode
26 }
27
28 static LazyAndWeak<JSONGrammar> _instance = new LazyAndWeak<JSONGrammar>(() => new JSONGrammar());
29
30 public static JSONGrammar Instance {
31 get { return _instance.Value; }
32 }
33
34 readonly ScannerContext<TokenType> m_jsonExpression;
35 readonly ScannerContext<TokenType> m_stringExpression;
36 readonly CharAlphabet m_defaultAlphabet = new CharAlphabet();
37
38 public JSONGrammar() {
39 DefineAlphabet(Enumerable.Range(0, 0x20).Select(x => (char)x));
40 var hexDigit = SymbolRangeToken('a','f').Or(SymbolRangeToken('A','F')).Or(SymbolRangeToken('0','9'));
41 var digit9 = SymbolRangeToken('1', '9');
42 var zero = SymbolToken('0');
43 var digit = zero.Or(digit9);
44 var dot = SymbolToken('.');
45 var minus = SymbolToken('-');
46 var sign = SymbolSetToken('-', '+');
47 var expSign = SymbolSetToken('e', 'E');
48 var letters = SymbolRangeToken('a', 'z');
49 var integer = zero.Or(digit9.Cat(digit.EClosure()));
50 var frac = dot.Cat(digit.Closure());
51 var exp = expSign.Cat(sign.Optional()).Cat(digit.Closure());
52 var quote = SymbolToken('"');
53 var backSlash = SymbolToken('\\');
54 var specialEscapeChars = SymbolSetToken('\\', '"', '/', 'b', 'f', 't', 'n', 'r');
55 var unicodeEspace = SymbolToken('u').Cat(hexDigit.Repeat(4));
56 var whitespace = SymbolSetToken('\n', '\r', '\t', ' ').EClosure();
57 var beginObject = whitespace.Cat(SymbolToken('{')).Cat(whitespace);
58 var endObject = whitespace.Cat(SymbolToken('}')).Cat(whitespace);
59 var beginArray = whitespace.Cat(SymbolToken('[')).Cat(whitespace);
60 var endArray = whitespace.Cat(SymbolToken(']')).Cat(whitespace);
61 var nameSep = whitespace.Cat(SymbolToken(':')).Cat(whitespace);
62 var valueSep = whitespace.Cat(SymbolToken(',')).Cat(whitespace);
63
64 var number = minus.Optional().Cat(integer).Cat(frac.Optional()).Cat(exp.Optional());
65 var literal = letters.Closure();
66 var unescaped = SymbolTokenExcept(Enumerable.Range(0, 0x20).Union(new int[] { '\\', '"' }).Select(x => (char)x));
67
68 var jsonExpression =
69 number.Tag(TokenType.Number)
70 .Or(literal.Tag(TokenType.Literal))
71 .Or(quote.Tag(TokenType.StringBound))
72 .Or(beginObject.Tag(TokenType.BeginObject))
73 .Or(endObject.Tag(TokenType.EndObject))
74 .Or(beginArray.Tag(TokenType.BeginArray))
75 .Or(endArray.Tag(TokenType.EndArray))
76 .Or(nameSep.Tag(TokenType.NameSeparator))
77 .Or(valueSep.Tag(TokenType.ValueSeparator))
78 .Or(SymbolSetToken('\n', '\r', '\t', ' ').Closure().Tag(TokenType.Whitespace));
79
80
81 var jsonStringExpression =
82 quote.Tag(TokenType.StringBound)
83 .Or(backSlash.Cat(specialEscapeChars).Tag(TokenType.EscapedChar))
84 .Or(backSlash.Cat(unicodeEspace).Tag(TokenType.EscapedUnicode))
85 .Or(unescaped.Closure().Tag(TokenType.UnescapedChar));
86
87
88 m_jsonExpression = BuildScannerContext<TokenType>(jsonExpression);
89 m_stringExpression = BuildScannerContext<TokenType>(jsonStringExpression);
90
91
92 }
93
94 protected override IAlphabetBuilder<char> AlphabetBuilder {
95 get {
96 return m_defaultAlphabet;
97 }
98 }
99
100 public ScannerContext<TokenType> JsonExpression {
101 get {
102 return m_jsonExpression;
103 }
104 }
105
106 public ScannerContext<TokenType> JsonStringExpression {
107 get {
108 return m_stringExpression;
109 }
110 }
111
112 Token SymbolRangeToken(char start, char stop) {
113 return SymbolToken(Enumerable.Range(start, stop - start + 1).Select(x => (char)x));
114 }
115
116 protected override IndexedAlphabetBase<char> CreateAlphabet() {
117 return new CharAlphabet();
118 }
119
120 }
121 }