Mercurial > pub > ImplabNet

comparison Implab/Formats/JSON/StringTranslator.cs @ 163:419aa51b04fd ref20160224

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JSON moved to Formats namespace Working in RegularDFA
author cin
date Wed, 24 Feb 2016 20:12:52 +0300
parents
children 0c3c69fe225b
comparison
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162:0526412bbb26 163:419aa51b04fd
1 using Implab;
2 using Implab.Parsing;
3 using System;
4 using System.Collections.Generic;
5 using System.Diagnostics;
6 using System.Linq;
7 using System.Text;
8 using System.Threading.Tasks;
9
10 namespace Implab.JSON {
11 /// <summary>
12 /// Класс для преобразования экранированной строки JSON
13 /// </summary>
14 public class StringTranslator : Scanner {
15 static readonly char[] _escMap;
16 static readonly int[] _hexMap;
17
18 static StringTranslator() {
19 var chars = new char[] { 'b', 'f', 't', 'r', 'n', '\\', '/' };
20 var vals = new char[] { '\b', '\f', '\t', '\r', '\n', '\\', '/' };
21
22 _escMap = new char[chars.Max() + 1];
23
24 for (int i = 0; i < chars.Length; i++)
25 _escMap[chars[i]] = vals[i];
26
27 var hexs = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'A', 'B', 'C', 'D', 'E', 'F' };
28 var ints = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 10, 11, 12, 13, 14, 15 };
29
30 _hexMap = new int[hexs.Max() + 1];
31
32 for (int i = 0; i < hexs.Length; i++)
33 _hexMap[hexs[i]] = ints[i];
34
35 }
36
37 public StringTranslator()
38 : base(JSONGrammar.Instance.JsonStringDFA.States, JSONGrammar.Instance.JsonStringDFA.Alphabet.GetTranslationMap()) {
39 }
40
41 public string Translate(string data) {
42 Safe.ArgumentNotNull(data, "data");
43 return Translate(data.ToCharArray());
44 }
45
46 public string Translate(char[] data) {
47 Safe.ArgumentNotNull(data, "data");
48 return Translate(data, data.Length);
49 }
50
51 public string Translate(char[] data, int length) {
52 Safe.ArgumentNotNull(data, "data");
53 Safe.ArgumentInRange(length, 0, data.Length, "length");
54
55 var translated = new char[length];
56
57 Feed(data,length);
58
59 int pos = 0;
60
61 while (ReadTokenInternal()) {
62 switch ((JSONGrammar.TokenType)TokenTags[0]) {
63 case JSONGrammar.TokenType.UnescapedChar:
64 Array.Copy(m_buffer,m_tokenOffset,translated,pos,m_tokenLen);
65 pos += m_tokenLen;
66 break;
67 case JSONGrammar.TokenType.EscapedChar:
68 translated[pos] = _escMap[m_buffer[m_tokenOffset + 1]];
69 pos++;
70 break;
71 case JSONGrammar.TokenType.EscapedUnicode:
72 translated[pos] = TranslateHexUnicode(m_buffer,m_tokenOffset + 2);
73 pos++;
74 break;
75 }
76 }
77
78 return new String(translated, 0, pos);
79 }
80
81 internal static char TranslateEscapedChar(char symbol) {
82 return _escMap[symbol];
83 }
84
85 internal static char TranslateHexUnicode(char[] symbols, int offset) {
86 Debug.Assert(symbols != null);
87 Debug.Assert(symbols.Length - offset >= 4);
88
89 int value = (_hexMap[symbols[offset]] << 12)
90 | (_hexMap[symbols[offset + 1]] << 8)
91 | (_hexMap[symbols[offset + 2]] << 4)
92 | (_hexMap[symbols[offset + 3]]);
93 return (char)value;
94 }
95 }
96 }