Squirrel JSON Parser

This library parses JSON into Squirrel data types.

To add this library to your project, add #require "JSONParser.class.nut:1.0.0" to the top of your code.

Usage

JSONParser has no constructor and one public function, parse().

parse(jsonString[, converterFunction])

The parse() method takes one required parameter, a JSON encoded string, and one optional parameter: a function used to convert custom types. The method returns a deserialized version of the object that was passed in.

Basic Example

local jsonString = "{\"one\" : 1}";
result <- JSONParser.parse(jsonString);
server.log(result.one);
// Displays '1'

Custom Types Converter

The optional converter function can be used to deserialize custom types. It takes two parameters:

• value — String representation of a value
• type — String indicating conversion type: "string" or "number"

For example, the following code converts all numbers to floats and makes strings uppercase:

result <- JSONParser.parse(jsonString, function (value, type) {
  if (type == "number") {
    return val.tofloat();
  } else if (type == "string") {
    return val.toupper();
  }
});

Extended Example:

class MyCustomType {
  _value = null;

 constructor(value) {
    this._value = value;
  }

  function _serialize() {
    return "@mycustomtype:" + this._value;
  }

  function getValue() {
    return this._value;
  }
}

o <- {a = 1, b = "Something", c = MyCustomType("100500") };
s <- JSONEncoder.encode(o);

server.log(s);
// Displays '{"a":1,"c":"@mycustomtype:100500","b":"Something"}'

result <- JSONParser.parse(s, function (val, type) {
  if ("number" == type) {
    return val.tofloat();
  } else if ("string" == type) {
    if (null != val.find("@mycustomtype")) {
      // Convert my custom type
      val = MyCustomType(val.slice(14))
    }

    return val;
  }
});

server.log(result.c instanceof MyCustomType);
// Displays 'true'

server.log(result.c.getValue());
// Displays '100500'

Testing

Repository contains impUnit tests and a configuration for impTest tool.

Tests can be launched with:

imptest test

By default configuration for the testing is read from .imptest.

To run test with your settings (for example while you are developing), create your copy of .imptest file and name it something like .imptest.local, then run tests with:

imptest test -c .imptest.local

Tests do not require any specific hardware.

License

The code in this repository is licensed under MIT License. Partially based on Douglas Crockford's state-machine JSON parser available as public domain.