""" Pipelines package interfaces.

$Id$
"""
from zope.interface import Interface

# which base exception? Define interface + implements?
class AbortPipelineException(Exception):
    """ A filter is notifying the pipeline shoud abort """

class IPipeline(Interface):

    def __call__(data):
        """ Entry point for event notification
        """

    def processFilters(data):
        """ Process our pipeline, allowing each filter to handle 'data'.
        """

class IFilter(Interface):

    def __call__(data, state):
        """ Do something to 'data', optionally store intermediate results
            and working data in 'state'

        o No return value expected.
        """