xson

Installation

$ npm install xson

Require

var xson = require('xson');

API

xson.parse(string [, options])

Parse an XSON string and return the result. Valid options keys:

• constructors: a map of object type names to their constructor functions. Whenever the XSON parser encounters a named object (or indeed a vector or money), the corresponding constructor will be called receiving the object's properties as a parameter. For example, to handle the following XSON:

  Person(name: "Jason")

one would call parse in the following manner:

```
xson.parse('Person(name: "Jason")', {
	constructors: {
		Person: function(props) {
			return new PersonModel(props.name);
		}
	}
});
```

Note that despite the name "constructors", such functions are invoked by regular function calls, i.e. `Person(props)` and not `new Person(props)`.

xson.stringify(object, [, options])

Convert an object structure to an XSON string and return it. Valid options keys:

• toStructure: a function that is called whenever the serializer encounters a Javascript object type (excluding null and arrays) to determine how it should be encoded. Returns one of the following:

  • for money: ['money', major, minor, currency]. Major/minor should be integers and currency is an optional string.
  • for vectors: ['vec2', x, y] or ['vec3', x, y, z].
  • for named objects: ['ConstructorName', properties].
  • for all other objects, return null. XSON will then serialize the object as a dictionary (i.e. standard JSON object).

The default implementation of toStructure will detect XSON's built-in Money, Vec2 and Vec3 types and encode them accordingly. All other objects will be encoded as XSON dictionaries.

Syntax

Atomic Types

Boolean

In addition to standard JSON syntax, on, off, yes and no are acceptable:

true
false
on
off
yes
no

Dates

Date are expressed in ISO-8601. When time is also present seconds and milliseconds may be omitted for convience's sake. When so omitted, they default to zero.

2014-03-07
2014-03-07T23:02
2014-03-07T23:02:28
2014-03-07T23:02:28.123

Number

Standard integers and floats are supported:

128
12.3

In addition you may use hex and binary literals:

0xFF0F
0b11010111

Any numeric literals may increase readability by using _:

1_000_000

String

"this is a string"

Composite Types

Array

As per JSON.

[]
[1, 2, 3]
[$3GBP, $10.75USD]

Dictionaries

As per JSON objects. Quoting of keys is optional for simple identifiers.

{}
{foo: "bar"}
{"a key with spaces and punctuation!": false}

Money

The money type is denoted by a $ prefix followed by decimal number and optional currency.

$2
$2.50
$2.50USD

Objects

Objects are represented by a named constructor followed by a parenthesized property list. The format of the property list is identical to that of a dictionary.

Person(name: "Jason", location: "Glasgow")

Vectors

XSON supports 2- and 3- component numeric vectors:

<1,2>
<2.3,6.7,0>

TODO

• object references
• escaped unicode literals