corrade-vassal – Rev 1
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#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]);
}
}
}
}