gistfile1.txt

"""
Basic interface that all parsers should respect
"""

from abc import ABCMeta, abstractmethod
from six import with_metaclass


class Parser(with_metaclass(ABCMeta, object)):
    """
    Parsers follow the scikit fit/transform idiom. They are learned from some
    training data via the `fit()` function. Once fitted to the training data,
    they can be set loose on anything you might want to parse: the `transform`
    function will produce graphs from the EDUs.

    If the learning process is expensive, it would make sense to offer the
    ability to initialise a parser from a cached model
    """

    @abstractmethod
    def fit(self, mpack):
        """
        Extract whatever models or other information from the multipack
        that is necessary to make the parser operational

        Parameters
        ----------
        mpack : MultiPack
        """
        raise NotImplementedError


    @abstractmethod
    def transform(self, dpack):
        """
        Parse a single document into a list of N-best graphs (ordered
        by what the parser considers to be match quality, best first)

        Parameters
        ----------
        dpack: DataPack

        Returns
        -------
        predictions: [ [(string,string,string)] ]
            list of list of (id, id, label) tuples

            predictions are ordered by what the parser considers to be
            match quality, best first)
        """
        raise NotImplementedError


class Labeller(with_metaclass(ABCMeta, object)):
    """
    A labeller assigns labels to edges in a graph. Note, it may
    sometimes make sense to implement labellers that preserve
    pre-existing labels (ie. only rewriting the ones which have
    the `UNKNOWN` label).  Doing so would allow you to stack
    multiple labellers.
    """

    @abstractmethod
    def fit(self, mpack):
        """
        Extract whatever models or other information from the multipack
        that is necessary to make the labeller operational

        :type mpack: MultiPack
        """
        raise NotImplementedError


    @abstractmethod
    def transform(self, dpack):
        """
        Parse a single document into a list of N-best graphs (ordered
        by what the parser considers to be match quality, best first)

        :type dpack: DataPack

        :rtype [ [(string,string,string)] ]
        """
        raise NotImplementedError