Package org.apache.lucene.util.automaton
Class LevenshteinAutomata
java.lang.Object
org.apache.lucene.util.automaton.LevenshteinAutomata
Class to construct DFAs that match a word within some edit distance.
Implements the algorithm described in: Schulz and Mihov: Fast String Correction with Levenshtein Automata
- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Field Summary
Modifier and TypeFieldDescriptionstatic final int
Maximum edit distance this class can generate an automaton for. -
Constructor Summary
ConstructorDescriptionLevenshteinAutomata
(int[] word, int alphaMax, boolean withTranspositions) Expert: specify a custom maximum possible symbol (alphaMax); default is Character.MAX_CODE_POINT.LevenshteinAutomata
(String input, boolean withTranspositions) Create a new LevenshteinAutomata for some input String. -
Method Summary
Modifier and TypeMethodDescriptiontoAutomaton
(int n) Compute a DFA that accepts all strings within an edit distance ofn
.toAutomaton
(int n, String prefix) Compute a DFA that accepts all strings within an edit distance ofn
, matching the specified exact prefix.
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Field Details
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MAXIMUM_SUPPORTED_DISTANCE
public static final int MAXIMUM_SUPPORTED_DISTANCEMaximum edit distance this class can generate an automaton for.- See Also:
- NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
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Constructor Details
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LevenshteinAutomata
Create a new LevenshteinAutomata for some input String. Optionally count transpositions as a primitive edit. -
LevenshteinAutomata
public LevenshteinAutomata(int[] word, int alphaMax, boolean withTranspositions) Expert: specify a custom maximum possible symbol (alphaMax); default is Character.MAX_CODE_POINT.
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Method Details
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toAutomaton
Compute a DFA that accepts all strings within an edit distance ofn
.All automata have the following properties:
- They are deterministic (DFA).
- There are no transitions to dead states.
- They are not minimal (some transitions could be combined).
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toAutomaton
Compute a DFA that accepts all strings within an edit distance ofn
, matching the specified exact prefix.All automata have the following properties:
- They are deterministic (DFA).
- There are no transitions to dead states.
- They are not minimal (some transitions could be combined).
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