def __init__(self, base_field, length, default_encoder_name, default_decoder_name, metric='Hamming'):
"""
Initializes mandatory parameters that any linear code shares.
This method only exists for inheritance purposes as it initializes
parameters that need to be known by every linear code. The class
:class:`sage.coding.linear_code_no_metric.AbstractLinearCodeNoMetric`
should never be directly instantiated.
INPUT:
- ``base_field`` -- the base field of ``self``
- ``length`` -- the length of ``self`` (a Python int or a Sage Integer, must be > 0)
- ``default_encoder_name`` -- the name of the default encoder of ``self``
- ``default_decoder_name`` -- the name of the default decoder of ``self``
- ``metric`` -- (default: ``Hamming``) the metric of ``self``
"""
self._registered_encoders['Systematic'] = LinearCodeSystematicEncoder
if not base_field.is_field():
raise ValueError("'base_field' must be a field (and {} is not one)".format(base_field))
if not default_encoder_name in self._registered_encoders:
raise ValueError("You must set a valid encoder as default encoder for this code, by filling in the dictionary of registered encoders")
if not default_decoder_name in self._registered_decoders:
raise ValueError("You must set a valid decoder as default decoder for this code, by filling in the dictionary of registered decoders")
#if not self.dimension() <= length:
# raise ValueError("The dimension of the code can be at most its length, {}".format(length))
super(AbstractLinearCodeNoMetric, self).__init__(length, default_encoder_name, default_decoder_name, metric)
cat = Modules(base_field).FiniteDimensional().WithBasis().Finite()
facade_for = VectorSpace(base_field, self._length)
self.Element = type(facade_for.an_element()) #for when we made this a non-facade parent
Parent.__init__(self, base=base_field, facade=facade_for, category=cat)
