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A library for spelling-correction based on Levenshtein Automata.
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// Generated by delombok at Sun May 29 12:10:02 UTC 2016
package com.github.liblevenshtein.transducer;
import java.io.Serializable;
import com.github.liblevenshtein.transducer.factory.PositionFactory;
import com.github.liblevenshtein.transducer.factory.StateFactory;
/**
* Implements common logic shared among the position-transition functions, which
* for their specific algorithm take one of the positions in a state and a few
* parameters, and return all posible positions leading from that one, under the
* constraints of the given paramters and the Levenshtein algorithm.
* @author Dylon Edwards
* @since 2.1.0
*/
public abstract class PositionTransitionFunction implements Serializable {
private static final long serialVersionUID = 1L;
/**
* Builds and caches states for the transducer.
*/
protected StateFactory stateFactory;
/**
* Builds and caches positions for states in the transducer.
*/
protected PositionFactory positionFactory;
/**
* Returns the first index of the characteristic vector between indices, i and
* k, that is true. This corresponds to the first index of the relevant
* subword whose element is the character of interest.
* @param characteristicVector Contains relevant subwords, which are booleans
* denoting whether the index at their locations correspond to the character
* being sought.
* @param k Last index of {@code characteristicVector} to examine for the
* first index of the relevant subword whose element is the character of
* interest.
* @param i First index of {@code characteristicVector} to examine for the
* first index of the relevant subword whose element is the character of
* interest.
* @return If a character match exists in the relevant subword, the first
* index of the relevant subword whose element is it. Otherwise, -1 is
* returned if no match exists (in the relevant subword). Note that
* {@code characteristicVector} may have more elements than are examined.
*/
protected int indexOf(final boolean[] characteristicVector, final int k, final int i) {
for (int j = 0; j < k; ++j) {
if (characteristicVector[i + j]) {
return j;
}
}
return -1;
}
/**
* Returns a state with all the possible transitions from the current
* position.
* @param n Maximum number of errors to tolerate in spelling candidates.
* @param position Vector consisting of the current index of the spelling
* candidate, the number of errors accumulated up to that index, and
* (optionally) a flag specifying whether the position is a special kind as
* defined by its specific, Levenshtein algorithm (e.g. whether it is a
* transposition position, etc.).
* @param characteristicVector Relevant subwords consisting of booleans about
* whether the characters associated by their indices in the spelling
* candidate are the same as the character being sought from the query term.
* @param offset Offset for various operations within the transition function.
* @return New state consisting of all possible transitions for the given
* position, given the other paramters.
*/
public abstract State of(int n, Position position, boolean[] characteristicVector, int offset);
/**
* Builds and caches states for the transducer.
* @return this
*/
@java.lang.SuppressWarnings("all")
@edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
@javax.annotation.Generated("lombok")
public PositionTransitionFunction stateFactory(final StateFactory stateFactory) {
this.stateFactory = stateFactory;
return this;
}
/**
* Builds and caches positions for states in the transducer.
* @return this
*/
@java.lang.SuppressWarnings("all")
@edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
@javax.annotation.Generated("lombok")
public PositionTransitionFunction positionFactory(final PositionFactory positionFactory) {
this.positionFactory = positionFactory;
return this;
}
}