parses a .ase file and returns a list of colors and color groups

    `swatch.parse` reads in an ase file and converts it to a list of colors and
    palettes. colors are simple dicts of the form

    ```json
    {
        'name': u'color name',
        'type': u'Process',
        'data': {
            'mode': u'RGB',
            'values': [1.0, 1.0, 1.0]
        }
    }
    ```

    the values provided vary between color mode. For all color modes, the
    value is always a list of floats.

    RGB: three floats between [0,1]  corresponding to RGB.
    CMYK: four floats between [0,1] inclusive, corresponding to CMYK.
    Gray: one float between [0,1] with 1 being white, 0 being black.
    LAB: three floats. The first L, is ranged from 0,1. Both A and B are
    floats ranging from [-128.0,127.0]. I believe illustrator just crops
    these to whole values, though.

    Palettes (née Color Groups in Adobe Parlance) are also dicts, but they have an
    attribute named `swatches` which contains a list of colors contained within
    the palette.

    ```json
    {
        'name': u'accent colors',
        'type': u'Color Group',
        'swatches': [
            {color}, {color}, ..., {color}
        ]
    }
    ```

    Because Adobe Illustrator lets swatches exist either inside and outside
    of palettes, the output of swatch.parse is a list that may contain
    swatches and palettes, i.e. [ swatch* palette* ]

    Here's an example with a light grey swatch followed by a color group containing three

        >>> import swatch
        >>> swatch.parse("example.ase")
        [{'data': {'mode': u'Gray', 'values': [0.75]},
          'name': u'Light Grey',
          'type': u'Process'},
         {'name': u'Accent Colors',
          'swatches': [{'data': {'mode': u'CMYK',
             'values': [0.5279774069786072,
              0.24386966228485107,
              1.0,
              0.04303044080734253]},
            'name': u'Green',
            'type': u'Process'},
           {'data': {'mode': u'CMYK',
             'values': [0.6261844635009766,
              0.5890134572982788,
              3.051804378628731e-05,
              3.051804378628731e-05]},
            'name': u'Violet Process Global',
            'type': u'Global'},
           {'data': {'mode': u'LAB', 'values': [0.6000000238418579, -35.0, -5.0]},
            'name': u'Cyan Spot (global)',
            'type': u'Spot'}],
          'type': u'Color Group'}]

def parse(filename):
    """parses a .ase file and returns a list of colors and color groups

    `swatch.parse` reads in an ase file and converts it to a list of colors and
    palettes. colors are simple dicts of the form

    ```json
    {
        'name': u'color name',
        'type': u'Process',
        'data': {
            'mode': u'RGB',
            'values': [1.0, 1.0, 1.0]
        }
    }
    ```

    the values provided vary between color mode. For all color modes, the
    value is always a list of floats.

    RGB: three floats between [0,1]  corresponding to RGB.
    CMYK: four floats between [0,1] inclusive, corresponding to CMYK.
    Gray: one float between [0,1] with 1 being white, 0 being black.
    LAB: three floats. The first L, is ranged from 0,1. Both A and B are
    floats ranging from [-128.0,127.0]. I believe illustrator just crops
    these to whole values, though.

    Palettes (née Color Groups in Adobe Parlance) are also dicts, but they have an
    attribute named `swatches` which contains a list of colors contained within
    the palette.

    ```json
    {
        'name': u'accent colors',
        'type': u'Color Group',
        'swatches': [
            {color}, {color}, ..., {color}
        ]
    }
    ```

    Because Adobe Illustrator lets swatches exist either inside and outside
    of palettes, the output of swatch.parse is a list that may contain
    swatches and palettes, i.e. [ swatch* palette* ]

    Here's an example with a light grey swatch followed by a color group containing three

        >>> import swatch
        >>> swatch.parse("example.ase")
        [{'data': {'mode': u'Gray', 'values': [0.75]},
          'name': u'Light Grey',
          'type': u'Process'},
         {'name': u'Accent Colors',
          'swatches': [{'data': {'mode': u'CMYK',
             'values': [0.5279774069786072,
              0.24386966228485107,
              1.0,
              0.04303044080734253]},
            'name': u'Green',
            'type': u'Process'},
           {'data': {'mode': u'CMYK',
             'values': [0.6261844635009766,
              0.5890134572982788,
              3.051804378628731e-05,
              3.051804378628731e-05]},
            'name': u'Violet Process Global',
            'type': u'Global'},
           {'data': {'mode': u'LAB', 'values': [0.6000000238418579, -35.0, -5.0]},
            'name': u'Cyan Spot (global)',
            'type': u'Spot'}],
          'type': u'Color Group'}]
    """

    with open(filename, "rb") as data:
        header, v_major, v_minor, chunk_count = struct.unpack("!4sHHI", data.read(12))

        assert header == b"ASEF"
        assert (v_major, v_minor) == (1, 0)

        return [c for c in parser.parse_chunk(data)]