Package nltk :: Package parse :: Module chart :: Class AbstractChartRule

type AbstractChartRule

object --+    
         |    
ChartRuleI --+
             |
            AbstractChartRule

Known Subclasses:

An abstract base class for chart rules. AbstractChartRule provides:

A default implementation for apply, based on apply_iter.
A default implementation for apply_everywhere_iter, based on apply_iter.
A default implementation for apply_everywhere, based on apply_everywhere_iter. Currently, this implementation assumes that NUM_EDGES<=3.
A default implementation for __str__, which returns a name basd on the rule's class name.

Instance Methods

[hide private]

iter of EdgeI

apply_iter(self, chart, grammar, *edges)
Returns: A generator that will add edges licensed by this rule and the given edges to the chart, one at a time.

source code

iter of EdgeI

apply_everywhere_iter(self, chart, grammar)
Returns: A generator that will add all edges licensed by this rule, given the edges that are currently in the chart, one at a time.

source code

list of EdgeI

apply(self, chart, grammar, *edges)
Add the edges licensed by this rule and the given edges to the chart.

source code

list of EdgeI

apply_everywhere(self, chart, grammar)
Add all the edges licensed by this rule and the edges in the chart to the chart.

source code

__str__(self)

source code

Class Variables

[hide private]

Inherited from ChartRuleI: NUM_EDGES

Method Details

[hide private]

apply_iter(self, chart, grammar, *edges)

source code

Parameters:

edges - 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 of EdgeI

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.

Overrides: ChartRuleI.apply_iter

(inherited documentation)

apply_everywhere_iter(self, chart, grammar)

source code

Returns: iter of EdgeI: 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.
Overrides: ChartRuleI.apply_everywhere_iter: (inherited documentation)