##// END OF EJS Templates
DFA refactoring
DFA refactoring

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r158:130781364799 v2
r161:2a8466f0cb8a v2
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StringTranslator.cs
96 lines | 3.4 KiB | text/x-csharp | CSharpLexer
using Implab;
using Implab.Parsing;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Implab.JSON {
/// <summary>
/// Класс для преобразования экранированной строки JSON
/// </summary>
public class StringTranslator : Scanner {
static readonly char[] _escMap;
static readonly int[] _hexMap;
static StringTranslator() {
var chars = new char[] { 'b', 'f', 't', 'r', 'n', '\\', '/' };
var vals = new char[] { '\b', '\f', '\t', '\r', '\n', '\\', '/' };
_escMap = new char[chars.Max() + 1];
for (int i = 0; i < chars.Length; i++)
_escMap[chars[i]] = vals[i];
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' };
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 };
_hexMap = new int[hexs.Max() + 1];
for (int i = 0; i < hexs.Length; i++)
_hexMap[hexs[i]] = ints[i];
}
public StringTranslator()
: base(JSONGrammar.Instance.JsonStringDFA.States, JSONGrammar.Instance.JsonStringDFA.Alphabet.GetTranslationMap()) {
}
public string Translate(string data) {
Safe.ArgumentNotNull(data, "data");
return Translate(data.ToCharArray());
}
public string Translate(char[] data) {
Safe.ArgumentNotNull(data, "data");
return Translate(data, data.Length);
}
public string Translate(char[] data, int length) {
Safe.ArgumentNotNull(data, "data");
Safe.ArgumentInRange(length, 0, data.Length, "length");
var translated = new char[length];
Feed(data,length);
int pos = 0;
while (ReadTokenInternal()) {
switch ((JSONGrammar.TokenType)TokenTags[0]) {
case JSONGrammar.TokenType.UnescapedChar:
Array.Copy(m_buffer,m_tokenOffset,translated,pos,m_tokenLen);
pos += m_tokenLen;
break;
case JSONGrammar.TokenType.EscapedChar:
translated[pos] = _escMap[m_buffer[m_tokenOffset + 1]];
pos++;
break;
case JSONGrammar.TokenType.EscapedUnicode:
translated[pos] = TranslateHexUnicode(m_buffer,m_tokenOffset + 2);
pos++;
break;
}
}
return new String(translated, 0, pos);
}
internal static char TranslateEscapedChar(char symbol) {
return _escMap[symbol];
}
internal static char TranslateHexUnicode(char[] symbols, int offset) {
Debug.Assert(symbols != null);
Debug.Assert(symbols.Length - offset >= 4);
int value = (_hexMap[symbols[offset]] << 12)
| (_hexMap[symbols[offset + 1]] << 8)
| (_hexMap[symbols[offset + 2]] << 4)
| (_hexMap[symbols[offset + 3]]);
return (char)value;
}
}
}