com.github.dylon.liblevenshtein.levenshtein.StateTransitionFunction Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of liblevenshtein Show documentation
A library for spelling-correction based on Levenshtein Automata.
The newest version!
// Generated by delombok at Sat Apr 30 14:43:05 PDT 2016
package com.github.dylon.liblevenshtein.levenshtein;

import java.io.Serializable;
import java.util.Comparator;
import com.github.dylon.liblevenshtein.levenshtein.factory.IPositionTransitionFactory;
import com.github.dylon.liblevenshtein.levenshtein.factory.IStateFactory;

/**
 * Transitions one state to another, given a set of inputs.  This function
 * doesn't need to know about the Levenshtein algorithm, as the
 * algorithm-specific components are injected via setters.
 * @author Dylon Edwards
 * @since 2.1.0
 */
public class StateTransitionFunction implements IStateTransitionFunction, Serializable {
  private static final long serialVersionUID = 1L;
  /**
   * Sorts {@link IState} elements in an unsubsumption-friendly fashion.
   */
  private Comparator comparator;
  /**
   * Builds and recycles {@link IState} instances.
   */
  private IStateFactory stateFactory;
  /**
   * Builds position vector, transition functions according to the Levenshtein
   * algorithm.
   */
  private IPositionTransitionFactory transitionFactory;
  /**
   * Merges states together according to the Levenshtein algorithm.
   */
  private IMergeFunction merge;
  /**
   * Removes positions from a state that are subsumed by other positions in that
   * state.
   */
  private IUnsubsumeFunction unsubsume;
  /**
   * Max number of errors tolerated in spelling candidates, from the query term.
   */
  private int maxDistance;

  /**
   * {@inheritDoc}
   */
  @Override
  public IState of(final IState currState, final boolean[] characteristicVector) {
    final IPositionTransitionFunction transition = transitionFactory.build();
    final int offset = currState.getOuter(0)[0];
    final IState nextState = stateFactory.build();
    final int n = maxDistance;
    for (int m = 0; m < currState.size(); ++m) {
      final IState positions = transition.of(n, currState.getOuter(m), characteristicVector, offset);
      if (null == positions) {
        continue;
      }
      merge.into(nextState, positions);
    }
    unsubsume.at(nextState);
    if (nextState.size() > 0) {
      nextState.sort(comparator);
      return nextState;
    }
    return null;
  }

  /**
   * Sorts {@link IState} elements in an unsubsumption-friendly fashion.
   * @param comparator Sorts {@link IState} elements in an unsubsumption-friendly fashion.
   * @return This {@link StateTransitionFunction} for fluency.
   */
  @java.lang.SuppressWarnings("all")
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
  @javax.annotation.Generated("lombok")
  public StateTransitionFunction comparator(final Comparator comparator) {
    this.comparator = comparator;
    return this;
  }

  /**
   * Builds and recycles {@link IState} instances.
   * @param stateFactory Builds and recycles {@link IState} instances.
   * @return This {@link StateTransitionFunction} for fluency.
   */
  @java.lang.SuppressWarnings("all")
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
  @javax.annotation.Generated("lombok")
  public StateTransitionFunction stateFactory(final IStateFactory stateFactory) {
    this.stateFactory = stateFactory;
    return this;
  }

  /**
   * Builds position vector, transition functions according to the Levenshtein
   * algorithm.
   * @param transitionFactory Builds position vector, transition functions
   * according to the Levenshtein algorithm.
   * @return This {@link StateTransitionFunction} for fluency.
   */
  @java.lang.SuppressWarnings("all")
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
  @javax.annotation.Generated("lombok")
  public StateTransitionFunction transitionFactory(final IPositionTransitionFactory transitionFactory) {
    this.transitionFactory = transitionFactory;
    return this;
  }

  /**
   * Merges states together according to the Levenshtein algorithm.
   * @param merge Merges states together according to the Levenshtein algorithm.
   * @return This {@link StateTransitionFunction} for fluency.
   */
  @java.lang.SuppressWarnings("all")
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
  @javax.annotation.Generated("lombok")
  public StateTransitionFunction merge(final IMergeFunction merge) {
    this.merge = merge;
    return this;
  }

  /**
   * Removes positions from a state that are subsumed by other positions in that
   * state.
   * @param unsubsume Removes positions from a state that are subsumed by other
   * positions in that state.
   * @return This {@link StateTransitionFunction} for fluency.
   */
  @java.lang.SuppressWarnings("all")
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
  @javax.annotation.Generated("lombok")
  public StateTransitionFunction unsubsume(final IUnsubsumeFunction unsubsume) {
    this.unsubsume = unsubsume;
    return this;
  }

  /**
   * Max number of errors tolerated in spelling candidates, from the query term.
   * @param maxDistance Max number of errors tolerated in spelling candidates,
   * from the query term.
   * @return This {@link StateTransitionFunction} for fluency.
   */
  @java.lang.SuppressWarnings("all")
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(justification = "generated code")
  @javax.annotation.Generated("lombok")
  public StateTransitionFunction maxDistance(final int maxDistance) {
    this.maxDistance = maxDistance;
    return this;
  }
}