Module earleychart
source code
Data classes and parser implementations for incremental chart
parsers, which use dynamic programming to efficiently parse a text. A chart parser
derives parse trees for a text by iteratively adding "edges" to
a "chart". Each edge represents a hypothesis about the tree
structure for a subsequence of the text. The chart is a
"blackboard" for composing and combining these hypotheses.
A parser is incremental, if it guarantees that for all i, j
where i < j, all edges ending at i are built before any edges ending
at j. This is appealing for, say, speech recognizer hypothesis
filtering.
The main parser class is EarleyChartParser, which is a top-down algorithm,
originally formulated by Jay Earley (1970).
|
|
demo(should_print_times=True,
should_print_grammar=False,
should_print_trees=True,
trace=2,
sent='I saw John with a dog with my cookie',
numparses=5)
A demonstration of the Earley parsers. |
source code
|
|
|
|
EARLEY_STRATEGY = [LeafInitRule(), TopDownInitRule(), Complete...
|
|
|
TD_INCREMENTAL_STRATEGY = [LeafInitRule(), TopDownInitRule(), ...
|
|
|
BU_INCREMENTAL_STRATEGY = [LeafInitRule(), EmptyPredictRule(),...
|
|
|
BU_LC_INCREMENTAL_STRATEGY = BU_LC_INCREMENTAL_STRATEGY
|
|
|
LC_INCREMENTAL_STRATEGY = [LeafInitRule(), FilteredBottomUpPre...
|
|
|
EARLEY_FEATURE_STRATEGY = [LeafInitRule(), FeatureTopDownInitR...
|
|
|
TD_INCREMENTAL_FEATURE_STRATEGY = [LeafInitRule(), FeatureTopD...
|
|
|
BU_INCREMENTAL_FEATURE_STRATEGY = [LeafInitRule(), FeatureEmpt...
|
|
|
BU_LC_INCREMENTAL_FEATURE_STRATEGY = [LeafInitRule(), FeatureE...
|
EARLEY_STRATEGY
- Value:
[LeafInitRule(), TopDownInitRule(), CompleterRule(), ScannerRule(), Pr
edictorRule()]
|
|
TD_INCREMENTAL_STRATEGY
- Value:
[LeafInitRule(), TopDownInitRule(), CachedTopDownPredictRule(), Comple
teFundamentalRule()]
|
|
BU_INCREMENTAL_STRATEGY
- Value:
[LeafInitRule(), EmptyPredictRule(), BottomUpPredictRule(), CompleteFu
ndamentalRule()]
|
|
LC_INCREMENTAL_STRATEGY
- Value:
[LeafInitRule(), FilteredBottomUpPredictCombineRule(), FilteredComplet
eFundamentalRule()]
|
|
EARLEY_FEATURE_STRATEGY
- Value:
[LeafInitRule(), FeatureTopDownInitRule(), FeatureCompleterRule(), Fea
tureScannerRule(), FeaturePredictorRule()]
|
|
TD_INCREMENTAL_FEATURE_STRATEGY
- Value:
[LeafInitRule(), FeatureTopDownInitRule(), FeatureTopDownPredictRule()
, FeatureCompleteFundamentalRule()]
|
|
BU_INCREMENTAL_FEATURE_STRATEGY
- Value:
[LeafInitRule(), FeatureEmptyPredictRule(), FeatureBottomUpPredictRule
(), FeatureCompleteFundamentalRule()]
|
|
BU_LC_INCREMENTAL_FEATURE_STRATEGY
- Value:
[LeafInitRule(), FeatureEmptyPredictRule(), FeatureBottomUpPredictComb
ineRule(), FeatureCompleteFundamentalRule()]
|
|