diff Implab/JSON/StringTranslator.cs @ 55:c0bf853aa04f

Added initial JSON support +JSONParser +JSONWriter
author cin
date Sun, 15 Jun 2014 19:39:11 +0400
parents
children 130781364799
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab/JSON/StringTranslator.cs	Sun Jun 15 19:39:11 2014 +0400
@@ -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) {
+        }
+
+        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;
+        }
+    }
+}