Mercurial > pub > ImplabNet
diff Implab/Formats/JSON/StringTranslator.cs @ 163:419aa51b04fd ref20160224
JSON moved to Formats namespace
Working in RegularDFA
author | cin |
---|---|
date | Wed, 24 Feb 2016 20:12:52 +0300 |
parents | |
children | 0c3c69fe225b |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Implab/Formats/JSON/StringTranslator.cs Wed Feb 24 20:12:52 2016 +0300 @@ -0,0 +1,96 @@ +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; + } + } +}