jyson

h1. Compliance of jyson

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There are two main areas where jyson needs to be compliant.

h2. RFC 4627

JSON was originally specified with a simple syntax diagram on "JSON.org":http://json.org

As JSON became more and more widely used, an internet RFC was published by Douglas Crockford, the original creator of JSON. That document is "RFC 4627":http://www.ietf.org/rfc/rfc4627.txt , which is now the definitive specification for JSON.

I am currently conducting a review of jyson's compliance with RFC 4627.

h2. The cpython json module.

I originally wrote jyson back in 2005, and devised my own API.

Now, there is a "json module":http://docs.python.org/library/json.html in the cpython standard library, as of version 2.6. Which means that jython will need to have a json module when it reaches version 2.6. This may be achieved by running the pure python version of the json module (the cpython json module relies on C extensions for some of it's speed).

But the C extensions won't run on jython, meaning that jython will suffer a speed penalty running the existing pure python module.

If jyson can be made to implement the same API as the cpython json module, then I will contribute the module to jython.

Here is a list of the main areas in which there are differences between the APIs

h3. Output to file-like objects

The "cpython json module":http://docs.python.org/library/json.html has facilities for the user to decode from and encode to file-like objects, as well as strings. 

Jyson only supports decoding from and encoding to strings: how those strings are transcoded for storage or rx/tx over a network is left to user.

h3. Character encodings

Because the "cpython json module":http://docs.python.org/library/json.html supports encoding and decoding from file-like objects, it has no choice but to concern itself with character encodings, since file-like objects are byte-oriented.

Jyson leaves the task of character encoding to the user. For example, the character encoding of a JSON document might be declared in a HTTP header, which is available to the programmer, but not to jyson.

When JSON was originally created, it contained no specifications for character encoding. However, "RFC 4627":http://www.ietf.org/rfc/rfc4627.txt now contains specifications of how JSON codecs should behave in relation to character encodings, and so jyson will have to the same.

h3. Incremental support

The "cpython json module":http://docs.python.org/library/json.html supports for generating JSON documents incrementally, i.e. in a series of smaller parts.

Jyson was originally written before jython supported generators, and this does not support this usage pattern.