Package org.apache.lucene.analysis
Class AutomatonToTokenStream
java.lang.Object
org.apache.lucene.analysis.AutomatonToTokenStream
Converts an Automaton into a TokenStream.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate static class
Edge between position nodes.private static class
Node that contains original node id and position in TokenStreamprivate static class
Token Stream that outputs tokens from a topo sorted graph. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic TokenStream
toTokenStream
(Automaton automaton) converts an automaton into a TokenStream.
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Constructor Details
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AutomatonToTokenStream
private AutomatonToTokenStream()
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Method Details
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toTokenStream
converts an automaton into a TokenStream. This is done by first Topo sorting the nodes in the Automaton. Nodes that have the same distance from the start are grouped together to form the position nodes for the TokenStream. The resulting TokenStream releases edges from the automaton as tokens in order from the position nodes. This requires the automaton be a finite DAG.- Parameters:
automaton
- automaton to convert. Must be a finite DAG.- Returns:
- TokenStream representation of automaton.
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