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Unity3D: MiniJSON Decodes and encodes simple JSON strings. Not intended for use with massive JSON strings, probably < 32k preferred. Handy for parsing JSON from inside Unity3d.
/*
* Copyright (c) 2013 Calvin Rien
*
* Based on the JSON parser by Patrick van Bergen
* http://techblog.procurios.nl/k/618/news/view/14605/14863/How-do-I-write-my-own-parser-for-JSON.html
*
* Simplified it so that it doesn't throw exceptions
* and can be used in Unity iPhone with maximum code stripping.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text;
namespace MiniJSON {
// Example usage:
//
// using UnityEngine;
// using System.Collections;
// using System.Collections.Generic;
// using MiniJSON;
//
// public class MiniJSONTest : MonoBehaviour {
// void Start () {
// var jsonString = "{ \"array\": [1.44,2,3], " +
// "\"object\": {\"key1\":\"value1\", \"key2\":256}, " +
// "\"string\": \"The quick brown fox \\\"jumps\\\" over the lazy dog \", " +
// "\"unicode\": \"\\u3041 Men\u00fa sesi\u00f3n\", " +
// "\"int\": 65536, " +
// "\"float\": 3.1415926, " +
// "\"bool\": true, " +
// "\"null\": null }";
//
// var dict = Json.Deserialize(jsonString) as Dictionary<string,object>;
//
// Debug.Log("deserialized: " + dict.GetType());
// Debug.Log("dict['array'][0]: " + ((List<object>) dict["array"])[0]);
// Debug.Log("dict['string']: " + (string) dict["string"]);
// Debug.Log("dict['float']: " + (double) dict["float"]); // floats come out as doubles
// Debug.Log("dict['int']: " + (long) dict["int"]); // ints come out as longs
// Debug.Log("dict['unicode']: " + (string) dict["unicode"]);
//
// var str = Json.Serialize(dict);
//
// Debug.Log("serialized: " + str);
// }
// }
/// <summary>
/// This class encodes and decodes JSON strings.
/// Spec. details, see http://www.json.org/
///
/// JSON uses Arrays and Objects. These correspond here to the datatypes IList and IDictionary.
/// All numbers are parsed to doubles.
/// </summary>
public static class Json {
/// <summary>
/// Parses the string json into a value
/// </summary>
/// <param name="json">A JSON string.</param>
/// <returns>An List&lt;object&gt;, a Dictionary&lt;string, object&gt;, a double, an integer,a string, null, true, or false</returns>
public static object Deserialize(string json) {
// save the string for debug information
if (json == null) {
return null;
}
return Parser.Parse(json);
}
sealed class Parser : IDisposable {
const string WORD_BREAK = "{}[],:\"";
public static bool IsWordBreak(char c) {
return Char.IsWhiteSpace(c) || WORD_BREAK.IndexOf(c) != -1;
}
enum TOKEN {
NONE,
CURLY_OPEN,
CURLY_CLOSE,
SQUARED_OPEN,
SQUARED_CLOSE,
COLON,
COMMA,
STRING,
NUMBER,
TRUE,
FALSE,
NULL
};
StringReader json;
Parser(string jsonString) {
json = new StringReader(jsonString);
}
public static object Parse(string jsonString) {
using (var instance = new Parser(jsonString)) {
return instance.ParseValue();
}
}
public void Dispose() {
json.Dispose();
json = null;
}
Dictionary<string, object> ParseObject() {
Dictionary<string, object> table = new Dictionary<string, object>();
// ditch opening brace
json.Read();
// {
while (true) {
switch (NextToken) {
case TOKEN.NONE:
return null;
case TOKEN.COMMA:
continue;
case TOKEN.CURLY_CLOSE:
return table;
default:
// name
string name = ParseString();
if (name == null) {
return null;
}
// :
if (NextToken != TOKEN.COLON) {
return null;
}
// ditch the colon
json.Read();
// value
table[name] = ParseValue();
break;
}
}
}
List<object> ParseArray() {
List<object> array = new List<object>();
// ditch opening bracket
json.Read();
// [
var parsing = true;
while (parsing) {
TOKEN nextToken = NextToken;
switch (nextToken) {
case TOKEN.NONE:
return null;
case TOKEN.COMMA:
continue;
case TOKEN.SQUARED_CLOSE:
parsing = false;
break;
default:
object value = ParseByToken(nextToken);
array.Add(value);
break;
}
}
return array;
}
object ParseValue() {
TOKEN nextToken = NextToken;
return ParseByToken(nextToken);
}
object ParseByToken(TOKEN token) {
switch (token) {
case TOKEN.STRING:
return ParseString();
case TOKEN.NUMBER:
return ParseNumber();
case TOKEN.CURLY_OPEN:
return ParseObject();
case TOKEN.SQUARED_OPEN:
return ParseArray();
case TOKEN.TRUE:
return true;
case TOKEN.FALSE:
return false;
case TOKEN.NULL:
return null;
default:
return null;
}
}
string ParseString() {
StringBuilder s = new StringBuilder();
char c;
// ditch opening quote
json.Read();
bool parsing = true;
while (parsing) {
if (json.Peek() == -1) {
parsing = false;
break;
}
c = NextChar;
switch (c) {
case '"':
parsing = false;
break;
case '\\':
if (json.Peek() == -1) {
parsing = false;
break;
}
c = NextChar;
switch (c) {
case '"':
case '\\':
case '/':
s.Append(c);
break;
case 'b':
s.Append('\b');
break;
case 'f':
s.Append('\f');
break;
case 'n':
s.Append('\n');
break;
case 'r':
s.Append('\r');
break;
case 't':
s.Append('\t');
break;
case 'u':
var hex = new char[4];
for (int i=0; i< 4; i++) {
hex[i] = NextChar;
}
s.Append((char) Convert.ToInt32(new string(hex), 16));
break;
}
break;
default:
s.Append(c);
break;
}
}
return s.ToString();
}
object ParseNumber() {
string number = NextWord;
if (number.IndexOf('.') == -1) {
long parsedInt;
Int64.TryParse(number, out parsedInt);
return parsedInt;
}
double parsedDouble;
Double.TryParse(number, out parsedDouble);
return parsedDouble;
}
void EatWhitespace() {
while (Char.IsWhiteSpace(PeekChar)) {
json.Read();
if (json.Peek() == -1) {
break;
}
}
}
char PeekChar {
get {
return Convert.ToChar(json.Peek());
}
}
char NextChar {
get {
return Convert.ToChar(json.Read());
}
}
string NextWord {
get {
StringBuilder word = new StringBuilder();
while (!IsWordBreak(PeekChar)) {
word.Append(NextChar);
if (json.Peek() == -1) {
break;
}
}
return word.ToString();
}
}
TOKEN NextToken {
get {
EatWhitespace();
if (json.Peek() == -1) {
return TOKEN.NONE;
}
switch (PeekChar) {
case '{':
return TOKEN.CURLY_OPEN;
case '}':
json.Read();
return TOKEN.CURLY_CLOSE;
case '[':
return TOKEN.SQUARED_OPEN;
case ']':
json.Read();
return TOKEN.SQUARED_CLOSE;
case ',':
json.Read();
return TOKEN.COMMA;
case '"':
return TOKEN.STRING;
case ':':
return TOKEN.COLON;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '-':
return TOKEN.NUMBER;
}
switch (NextWord) {
case "false":
return TOKEN.FALSE;
case "true":
return TOKEN.TRUE;
case "null":
return TOKEN.NULL;
}
return TOKEN.NONE;
}
}
}
/// <summary>
/// Converts a IDictionary / IList object or a simple type (string, int, etc.) into a JSON string
/// </summary>
/// <param name="json">A Dictionary&lt;string, object&gt; / List&lt;object&gt;</param>
/// <returns>A JSON encoded string, or null if object 'json' is not serializable</returns>
public static string Serialize(object obj) {
return Serializer.Serialize(obj);
}
sealed class Serializer {
StringBuilder builder;
Serializer() {
builder = new StringBuilder();
}
public static string Serialize(object obj) {
var instance = new Serializer();
instance.SerializeValue(obj);
return instance.builder.ToString();
}
void SerializeValue(object value) {
IList asList;
IDictionary asDict;
string asStr;
if (value == null) {
builder.Append("null");
} else if ((asStr = value as string) != null) {
SerializeString(asStr);
} else if (value is bool) {
builder.Append((bool) value ? "true" : "false");
} else if ((asList = value as IList) != null) {
SerializeArray(asList);
} else if ((asDict = value as IDictionary) != null) {
SerializeObject(asDict);
} else if (value is char) {
SerializeString(new string((char) value, 1));
} else {
SerializeOther(value);
}
}
void SerializeObject(IDictionary obj) {
bool first = true;
builder.Append('{');
foreach (object e in obj.Keys) {
if (!first) {
builder.Append(',');
}
SerializeString(e.ToString());
builder.Append(':');
SerializeValue(obj[e]);
first = false;
}
builder.Append('}');
}
void SerializeArray(IList anArray) {
builder.Append('[');
bool first = true;
foreach (object obj in anArray) {
if (!first) {
builder.Append(',');
}
SerializeValue(obj);
first = false;
}
builder.Append(']');
}
void SerializeString(string str) {
builder.Append('\"');
char[] charArray = str.ToCharArray();
foreach (var c in charArray) {
switch (c) {
case '"':
builder.Append("\\\"");
break;
case '\\':
builder.Append("\\\\");
break;
case '\b':
builder.Append("\\b");
break;
case '\f':
builder.Append("\\f");
break;
case '\n':
builder.Append("\\n");
break;
case '\r':
builder.Append("\\r");
break;
case '\t':
builder.Append("\\t");
break;
default:
int codepoint = Convert.ToInt32(c);
if ((codepoint >= 32) && (codepoint <= 126)) {
builder.Append(c);
} else {
builder.Append("\\u");
builder.Append(codepoint.ToString("x4"));
}
break;
}
}
builder.Append('\"');
}
void SerializeOther(object value) {
// NOTE: decimals lose precision during serialization.
// They always have, I'm just letting you know.
// Previously floats and doubles lost precision too.
if (value is float) {
builder.Append(((float) value).ToString("R"));
} else if (value is int
|| value is uint
|| value is long
|| value is sbyte
|| value is byte
|| value is short
|| value is ushort
|| value is ulong) {
builder.Append(value);
} else if (value is double
|| value is decimal) {
builder.Append(Convert.ToDouble(value).ToString("R"));
} else {
SerializeString(value.ToString());
}
}
}
}
}
@Draco18s
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Draco18s commented Jun 9, 2021

Your test isn't outputting valid JSON:

Oops, I was typing up a simple example (rather than actual code I'm using) and missed the extra pair of ". My actual code doesn't have that typo. Updated.

Your life will be better with a more modern parser.

The life of a modder. miniJson ships with my target, so miniJson it is.

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