nltk.parse.chart.AbstractChartRule

class documentation

class AbstractChartRule(ChartRuleI): (source)

Known subclasses: nltk.ccg.chart.BackwardTypeRaiseRule, nltk.ccg.chart.BinaryCombinatorRule, nltk.ccg.chart.ForwardTypeRaiseRule, nltk.parse.chart.BottomUpPredictRule, nltk.parse.chart.EmptyPredictRule, nltk.parse.chart.FundamentalRule, nltk.parse.chart.LeafInitRule, nltk.parse.chart.TopDownInitRule, nltk.parse.chart.TopDownPredictRule, nltk.parse.pchart.ProbabilisticBottomUpInitRule, nltk.parse.pchart.ProbabilisticBottomUpPredictRule, nltk.parse.pchart.ProbabilisticFundamentalRule, nltk.parse.pchart.SingleEdgeProbabilisticFundamentalRule

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An abstract base class for chart rules. AbstractChartRule provides:

  • A default implementation for apply.
  • A default implementation for apply_everywhere, (Currently, this implementation assumes that ``NUM_EDGES``<=3.)
  • A default implementation for __str__, which returns a name based on the rule's class name.
Method __str__ Undocumented
Method apply Return a generator that will add edges licensed by this rule and the given edges to the chart, one at a time. Each time the generator is resumed, it will either add a new edge and yield that edge; or return.
Method apply_everywhere Return a generator that will add all edges licensed by this rule, given the edges that are currently in the chart, one at a time. Each time the generator is resumed, it will either add a new edge and yield that edge; or return.

Inherited from ChartRuleI:

Class Variable NUM_EDGES The number of existing edges that this rule uses to license new edges. Typically, this number ranges from zero to two.
def __str__(self): (source)
overridden in nltk.ccg.chart.BackwardTypeRaiseRule, nltk.ccg.chart.BinaryCombinatorRule, nltk.ccg.chart.ForwardTypeRaiseRule, nltk.parse.pchart.SingleEdgeProbabilisticFundamentalRule

Undocumented

def apply(self, chart, grammar, *edges): (source)
overrides nltk.parse.chart.ChartRuleI.apply
overridden in nltk.ccg.chart.BackwardTypeRaiseRule, nltk.ccg.chart.BinaryCombinatorRule, nltk.ccg.chart.ForwardTypeRaiseRule, nltk.parse.chart.BottomUpPredictRule, nltk.parse.chart.EmptyPredictRule, nltk.parse.chart.FundamentalRule, nltk.parse.chart.LeafInitRule, nltk.parse.chart.TopDownInitRule, nltk.parse.chart.TopDownPredictRule, nltk.parse.pchart.ProbabilisticBottomUpInitRule, nltk.parse.pchart.ProbabilisticBottomUpPredictRule, nltk.parse.pchart.ProbabilisticFundamentalRule, nltk.parse.pchart.SingleEdgeProbabilisticFundamentalRule

Return a generator that will add edges licensed by this rule and the given edges to the chart, one at a time. Each time the generator is resumed, it will either add a new edge and yield that edge; or return.

Parameters
chartUndocumented
grammarUndocumented
*edges:list(EdgeI)A set of existing edges. The number of edges that should be passed to apply() is specified by the NUM_EDGES class variable.
Returns
iter(EdgeI)Undocumented
def apply_everywhere(self, chart, grammar): (source)
overrides nltk.parse.chart.ChartRuleI.apply_everywhere

Return a generator that will add all edges licensed by this rule, given the edges that are currently in the chart, one at a time. Each time the generator is resumed, it will either add a new edge and yield that edge; or return.

Returns
iter(EdgeI)Undocumented