JsonReader.cs :  » Development » LitJSON » LitJson » C# / CSharp Open Source

Home
C# / CSharp Open Source
1.2.6.4 mono .net core
2.2.6.4 mono core
3.Aspect Oriented Frameworks
4.Bloggers
5.Build Systems
6.Business Application
7.Charting Reporting Tools
8.Chat Servers
9.Code Coverage Tools
10.Content Management Systems CMS
11.CRM ERP
12.Database
13.Development
14.Email
15.Forum
16.Game
17.GIS
18.GUI
19.IDEs
20.Installers Generators
21.Inversion of Control Dependency Injection
22.Issue Tracking
23.Logging Tools
24.Message
25.Mobile
26.Network Clients
27.Network Servers
28.Office
29.PDF
30.Persistence Frameworks
31.Portals
32.Profilers
33.Project Management
34.RSS RDF
35.Rule Engines
36.Script
37.Search Engines
38.Sound Audio
39.Source Control
40.SQL Clients
41.Template Engines
42.Testing
43.UML
44.Web Frameworks
45.Web Service
46.Web Testing
47.Wiki Engines
48.Windows Presentation Foundation
49.Workflows
50.XML Parsers
C# / C Sharp
C# / C Sharp by API
C# / CSharp Tutorial
C# / CSharp Open Source » Development » LitJSON 
LitJSON » LitJson » JsonReader.cs
#region Header
/**
 * JsonReader.cs
 *   Stream-like access to JSON text.
 *
 * The authors disclaim copyright to this source code. For more details, see
 * the COPYING file included with this distribution.
 **/
#endregion


using System;
using System.Collections.Generic;
using System.IO;
using System.Text;


namespace LitJson{
    public enum JsonToken
    {
        None,

        ObjectStart,
        PropertyName,
        ObjectEnd,

        ArrayStart,
        ArrayEnd,

        Int,
        Long,
        Double,

        String,

        Boolean,
        Null
    }


    public class JsonReader
    {
        #region Fields
        private static IDictionary<int, IDictionary<int, int[]>> parse_table;

        private Stack<int>    automaton_stack;
        private int           current_input;
        private int           current_symbol;
        private bool          end_of_json;
        private bool          end_of_input;
        private Lexer         lexer;
        private bool          parser_in_string;
        private bool          parser_return;
        private bool          read_started;
        private TextReader    reader;
        private bool          reader_is_owned;
        private object        token_value;
        private JsonToken     token;
        #endregion


        #region Public Properties
        public bool AllowComments {
            get { return lexer.AllowComments; }
            set { lexer.AllowComments = value; }
        }

        public bool AllowSingleQuotedStrings {
            get { return lexer.AllowSingleQuotedStrings; }
            set { lexer.AllowSingleQuotedStrings = value; }
        }

        public bool EndOfInput {
            get { return end_of_input; }
        }

        public bool EndOfJson {
            get { return end_of_json; }
        }

        public JsonToken Token {
            get { return token; }
        }

        public object Value {
            get { return token_value; }
        }
        #endregion


        #region Constructors
        static JsonReader ()
        {
            PopulateParseTable ();
        }

        public JsonReader (string json_text) :
            this (new StringReader (json_text), true)
        {
        }

        public JsonReader (TextReader reader) :
            this (reader, false)
        {
        }

        private JsonReader (TextReader reader, bool owned)
        {
            if (reader == null)
                throw new ArgumentNullException ("reader");

            parser_in_string = false;
            parser_return = false;

            read_started = false;
            automaton_stack = new Stack<int> ();
            automaton_stack.Push ((int) ParserToken.End);
            automaton_stack.Push ((int) ParserToken.Text);

            lexer = new Lexer (reader);

            end_of_input = false;
            end_of_json  = false;

            this.reader = reader;
            reader_is_owned = owned;
        }
        #endregion


        #region Static Methods
        private static void PopulateParseTable ()
        {
            parse_table = new Dictionary<int, IDictionary<int, int[]>> ();

            TableAddRow (ParserToken.Array);
            TableAddCol (ParserToken.Array, '[',
                         '[',
                         (int) ParserToken.ArrayPrime);

            TableAddRow (ParserToken.ArrayPrime);
            TableAddCol (ParserToken.ArrayPrime, '"',
                         (int) ParserToken.Value,

                         (int) ParserToken.ValueRest,
                         ']');
            TableAddCol (ParserToken.ArrayPrime, '[',
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest,
                         ']');
            TableAddCol (ParserToken.ArrayPrime, ']',
                         ']');
            TableAddCol (ParserToken.ArrayPrime, '{',
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest,
                         ']');
            TableAddCol (ParserToken.ArrayPrime, (int) ParserToken.Number,
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest,
                         ']');
            TableAddCol (ParserToken.ArrayPrime, (int) ParserToken.True,
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest,
                         ']');
            TableAddCol (ParserToken.ArrayPrime, (int) ParserToken.False,
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest,
                         ']');
            TableAddCol (ParserToken.ArrayPrime, (int) ParserToken.Null,
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest,
                         ']');

            TableAddRow (ParserToken.Object);
            TableAddCol (ParserToken.Object, '{',
                         '{',
                         (int) ParserToken.ObjectPrime);

            TableAddRow (ParserToken.ObjectPrime);
            TableAddCol (ParserToken.ObjectPrime, '"',
                         (int) ParserToken.Pair,
                         (int) ParserToken.PairRest,
                         '}');
            TableAddCol (ParserToken.ObjectPrime, '}',
                         '}');

            TableAddRow (ParserToken.Pair);
            TableAddCol (ParserToken.Pair, '"',
                         (int) ParserToken.String,
                         ':',
                         (int) ParserToken.Value);

            TableAddRow (ParserToken.PairRest);
            TableAddCol (ParserToken.PairRest, ',',
                         ',',
                         (int) ParserToken.Pair,
                         (int) ParserToken.PairRest);
            TableAddCol (ParserToken.PairRest, '}',
                         (int) ParserToken.Epsilon);

            TableAddRow (ParserToken.String);
            TableAddCol (ParserToken.String, '"',
                         '"',
                         (int) ParserToken.CharSeq,
                         '"');

            TableAddRow (ParserToken.Text);
            TableAddCol (ParserToken.Text, '[',
                         (int) ParserToken.Array);
            TableAddCol (ParserToken.Text, '{',
                         (int) ParserToken.Object);

            TableAddRow (ParserToken.Value);
            TableAddCol (ParserToken.Value, '"',
                         (int) ParserToken.String);
            TableAddCol (ParserToken.Value, '[',
                         (int) ParserToken.Array);
            TableAddCol (ParserToken.Value, '{',
                         (int) ParserToken.Object);
            TableAddCol (ParserToken.Value, (int) ParserToken.Number,
                         (int) ParserToken.Number);
            TableAddCol (ParserToken.Value, (int) ParserToken.True,
                         (int) ParserToken.True);
            TableAddCol (ParserToken.Value, (int) ParserToken.False,
                         (int) ParserToken.False);
            TableAddCol (ParserToken.Value, (int) ParserToken.Null,
                         (int) ParserToken.Null);

            TableAddRow (ParserToken.ValueRest);
            TableAddCol (ParserToken.ValueRest, ',',
                         ',',
                         (int) ParserToken.Value,
                         (int) ParserToken.ValueRest);
            TableAddCol (ParserToken.ValueRest, ']',
                         (int) ParserToken.Epsilon);
        }

        private static void TableAddCol (ParserToken row, int col,
                                         params int[] symbols)
        {
            parse_table[(int) row].Add (col, symbols);
        }

        private static void TableAddRow (ParserToken rule)
        {
            parse_table.Add ((int) rule, new Dictionary<int, int[]> ());
        }
        #endregion


        #region Private Methods
        private void ProcessNumber (string number)
        {
            if (number.IndexOf ('.') != -1 ||
                number.IndexOf ('e') != -1 ||
                number.IndexOf ('E') != -1) {

                double n_double;
                if (Double.TryParse (number, out n_double)) {
                    token = JsonToken.Double;
                    token_value = n_double;

                    return;
                }
            }

            int n_int32;
            if (Int32.TryParse (number, out n_int32)) {
                token = JsonToken.Int;
                token_value = n_int32;

                return;
            }

            long n_int64;
            if (Int64.TryParse (number, out n_int64)) {
                token = JsonToken.Long;
                token_value = n_int64;

                return;
            }

            // Shouldn't happen, but just in case, return something
            token = JsonToken.Int;
            token_value = 0;
        }

        private void ProcessSymbol ()
        {
            if (current_symbol == '[')  {
                token = JsonToken.ArrayStart;
                parser_return = true;

            } else if (current_symbol == ']')  {
                token = JsonToken.ArrayEnd;
                parser_return = true;

            } else if (current_symbol == '{')  {
                token = JsonToken.ObjectStart;
                parser_return = true;

            } else if (current_symbol == '}')  {
                token = JsonToken.ObjectEnd;
                parser_return = true;

            } else if (current_symbol == '"')  {
                if (parser_in_string) {
                    parser_in_string = false;

                    parser_return = true;

                } else {
                    if (token == JsonToken.None)
                        token = JsonToken.String;

                    parser_in_string = true;
                }

            } else if (current_symbol == (int) ParserToken.CharSeq) {
                token_value = lexer.StringValue;

            } else if (current_symbol == (int) ParserToken.False)  {
                token = JsonToken.Boolean;
                token_value = false;
                parser_return = true;

            } else if (current_symbol == (int) ParserToken.Null)  {
                token = JsonToken.Null;
                parser_return = true;

            } else if (current_symbol == (int) ParserToken.Number)  {
                ProcessNumber (lexer.StringValue);

                parser_return = true;

            } else if (current_symbol == (int) ParserToken.Pair)  {
                token = JsonToken.PropertyName;

            } else if (current_symbol == (int) ParserToken.True)  {
                token = JsonToken.Boolean;
                token_value = true;
                parser_return = true;

            }
        }

        private bool ReadToken ()
        {
            if (end_of_input)
                return false;

            lexer.NextToken ();

            if (lexer.EndOfInput) {
                Close ();

                return false;
            }

            current_input = lexer.Token;

            return true;
        }
        #endregion


        public void Close ()
        {
            if (end_of_input)
                return;

            end_of_input = true;
            end_of_json  = true;

            if (reader_is_owned)
                reader.Close ();

            reader = null;
        }

        public bool Read ()
        {
            if (end_of_input)
                return false;

            if (end_of_json) {
                end_of_json = false;
                automaton_stack.Clear ();
                automaton_stack.Push ((int) ParserToken.End);
                automaton_stack.Push ((int) ParserToken.Text);
            }

            parser_in_string = false;
            parser_return    = false;

            token       = JsonToken.None;
            token_value = null;

            if (! read_started) {
                read_started = true;

                if (! ReadToken ())
                    return false;
            }


            int[] entry_symbols;

            while (true) {
                if (parser_return) {
                    if (automaton_stack.Peek () == (int) ParserToken.End)
                        end_of_json = true;

                    return true;
                }

                current_symbol = automaton_stack.Pop ();

                ProcessSymbol ();

                if (current_symbol == current_input) {
                    if (! ReadToken ()) {
                        if (automaton_stack.Peek () != (int) ParserToken.End)
                            throw new JsonException (
                                "Input doesn't evaluate to proper JSON text");

                        if (parser_return)
                            return true;

                        return false;
                    }

                    continue;
                }

                try {

                    entry_symbols =
                        parse_table[current_symbol][current_input];

                } catch (KeyNotFoundException e) {
                    throw new JsonException ((ParserToken) current_input, e);
                }

                if (entry_symbols[0] == (int) ParserToken.Epsilon)
                    continue;

                for (int i = entry_symbols.Length - 1; i >= 0; i--)
                    automaton_stack.Push (entry_symbols[i]);
            }
        }

    }
}
www.java2v.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.