JValue

Lightweight C# Json Parser.
JValue is simple and pure.

Features

• Pros
  • Small memory footprint. (no heap allocation)
  • Fastest parse.
  • Easy to install.
  • Easy to use.
  • Unity3D friendly.
  • Multithread safe. (JValue is immutable type)
• Cons
  • When you get to repeat the same key, it is inefficient.
  • Object mapping NOT supported. (System.Reflection)

Simple usage

JValue location = JValue.Parse(@"{""x"":10, ""y"":20}");
Console.WriteLine((int)location["x"]); // 10
Console.WriteLine((int)location["y"]); // 20
Console.WriteLine(location["z"].ToString()); // null

var person = new Dictionary<string, JValue>()
{
    {"name", "John"},
    {"age", 27},
};
Console.WriteLine(new JValue(person).ToString()); // {"name":"John","age":27}

Mechanism

1. JValue is struct.
2. JValue has three members. {string source, int startIndex, int length}

// raw source
// {"name":"John", "age":27, "friend":{"name":"Tom"}}
JValue person = JValue.Parse(...);
// person.source = ...
// person.startIndex = 0
// person.length = 50

JValue name = person["name"];
// name.source = person.source
// name.startIndex = 8
// name.length = 6

JValue age = person["age"];
// age.source = person.source
// age.startIndex = 22
// age.length = 2

JValue friend = person["friend"];
// friend.source = person.source
// friend.startIndex = 35
// friend.length = 14

JValue friendName = friend["name"];
// friendName.source = friend.source = person.source
// friendName.startIndex = 43
// friendName.length = 5

string nameValue = (string)name; // At this time, encode string.
int ageValue = (int)age; // At this time, parse int.

Usage

JValue book = JValue.Parse(@"{
    ""name"": ""Json guide"",
    ""pages"": 400,
    ""tags"": [""computer"", ""data-interchange format"", ""easy""],
    ""price"": {""usd"":0.99, ""krw"":1000}
}");
string name = book["name"];
Console.WriteLine("Name: {0}", name);

int pages = book["pages"];
Console.WriteLine("Pages: {0}", pages);

Console.WriteLine("Primary tag: {0}", book["tags"][0].AsString());
Console.WriteLine("Tags:");
foreach (var item in book["tags"].Array())
    Console.WriteLine("\t{0}", item);
Console.WriteLine("Unknown tag: {0}", book["tags"][100].AsString());

JValue price = book["price"];
Console.WriteLine("Price: ${0}", (double)price["usd"]);
Console.WriteLine("");
Console.WriteLine("Reserialization");
Console.WriteLine(book.Serialize(false));

/*
Name: Json guide
Pages: 400
Primary tag: computer
Tags:
        "computer"
        "data-interchange format"
        "easy"
Unknown author:
Price: $0.99

Reserialization
{"name":"Json guide","pages":400,"tags":["computer","data-interchange format","easy"],"price":{"usd":0.99,"krw":1000}}
*/