FeaturizerContextGenerator.java

/**
 * Copyright (C) 2012 cogroo <cogroo@cogroo.org>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.cogroo.tools.featurizer;

import org.cogroo.tools.chunker2.TokenTag;

import opennlp.tools.util.BeamSearchContextGenerator;

/**
 * Interface for the context generator used in syntactic chunking.
 */
public interface FeaturizerContextGenerator extends
    BeamSearchContextGenerator<TokenTag> {

  /**
   * Returns the contexts for chunking of the specified index.
   * 
   * @param i
   *          The index of the token in the specified toks array for which the
   *          context should be constructed.
   * @param toks
   *          The tokens of the sentence. The <code>toString</code> methods of
   *          these objects should return the token text.
   * @param tags
   *          The POS tags for the the specified tokens.
   * @param preds
   *          The previous decisions made in the taging of this sequence. Only
   *          indices less than i will be examined.
   * @return An array of predictive contexts on which a model basis its
   *         decisions.
   */
  public String[] getContext(int i, String[] toks, String[] tags, String[] preds);
}