Description

This is a implementation of the JSON specification according to RFC 4627. You can think of it as a low fat alternative to XML, if you want to store data to disk or transmit it over a network rather than use a verbose markup language.

Starting from version 1.0.0 on there will be two variants available:

• A pure ruby variant, that relies on the iconv and the stringscan extensions, which are both part of the ruby standard library.
• The quite a bit faster (see the documentation) C extension variant, which is in parts implemented in C and comes with its own unicode conversion functions and a parser generated by the Ragel State Machine Compiler.

Both variants of the JSON generator escape all non-ASCII an control characters with \uXXXX escape sequences, and support UTF-16 surrogate pairs in order to be able to generate the whole range of unicode code points. This means that generated JSON text is encoded as UTF-8 (because ASCII is a subset of UTF-8) and at the same time avoids decoding problems for receiving endpoints, that don't expect UTF-8 encoded texts. On the negative side this may lead to a bit longer strings than necessarry.

It's also easy to extend JSON data types for arbitrary Ruby classes (including your own) like this:

class Range
  def to_json(*a)
    {
      'json_class'   => self.class.name,
      'data'         => \[ first, last, exclude_end? ]
    }.to_json(*a)
  end

  def self.json_create(o)
    new(*o\['data'])
  end
end

Now Range instances can be serialized/deserialized:

JSON.parse((1..10).to_json) == (1..10)

A lot of additional information about JSON can be found Douglas Crockford's JSON site.