This module provides basic functions for handling mime-types. It can
handle matching mime-types against a list of media-ranges. See section
14.1 of the HTTP specification [RFC 2616] for a complete explanation.

  <http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1>

A port to JavaScript of Joe Gregorio's MIME-Type Parser:

  <http://code.google.com/p/mimeparse/>

Ported by J. Chris Anderson <[email protected]>, targeting the
Spidermonkey runtime.

Ported to Chiron, Narwhal, Node by Kris Kowal.

  <http://github.com/kriskowal/mimeparse>


Installation
============

    Install <http://github.com/isaacs/npm>

    npm install mimeparse


The API
=======

parseMimeType(mimeType)

    Carves up a mime-type and returns an Array of the
    [type, subtype, params] where "params" is a Hash of all
    the parameters for the media range.

    For example, the media range "application/xhtml;q=0.5" would
    get parsed into::

        ["application", "xhtml", { "q" : "0.5" }]

parseMediaRange(range)

    Carves up a media range and returns an Array of the
    [type, subtype, params] where "params" is a Object with
    all the parameters for the media range.
    
    For example, the media range "application/*;q=0.5" would
    get parsed into::
    
        ["application", "*", { "q" : "0.5" }]
    
    In addition this function also guarantees that there
    is a value for "q" in the params dictionary, filling it
    in with a proper default if necessary.

fitnessAndQualityParsed(mimeType, parsedRanges)

    Find the best match for a given mime-type against
    a list of media_ranges that have already been
    parsed by parseMediaRange(). Returns an array of
    the fitness value and the value of the 'q' quality
    parameter of the best match, or (-1, 0) if no match
    was found. Just as for qualityParsed(), 'parsed_ranges'
    must be a list of parsed media ranges.

qualityParsed(mimeType, parsedRanges)

    Find the best match for a given mime-type against
    a list of media_ranges that have already been
    parsed by parseMediaRange(). Returns the
    'q' quality parameter of the best match, 0 if no
    match was found. This function bahaves the same as quality()
    except that 'parsedRanges' must be a list of
    parsed media ranges.

quality(mimeType, ranges)

    Returns the quality 'q' of a mime-type when compared
    against the media-ranges in ranges. For example::

        >>> quality('text/html','text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, *\/*;q=0.5')
        0.7

bestMatch(supported, header)

    Takes a list of supported mime-types and finds the best
    match for all the media-ranges listed in header. The value of
    header must be a string that conforms to the format of the
    HTTP Accept: header. The value of 'supported' is a list of
    mime-types::
    
        >>> bestMatch(['application/xbel+xml', 'text/xml'], 'text/*;q=0.5,*\/*; q=0.1')
        'text/xml'