| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.lucene.search; |
| |
| import java.io.IOException; |
| |
| /** |
| * Base class for exact and sloppy phrase matching |
| * |
| * To find matches on a document, first advance {@link #approximation} to the |
| * relevant document, then call {@link #reset()}. Clients can then call |
| * {@link #nextMatch()} to iterate over the matches |
| */ |
| abstract class PhraseMatcher { |
| |
| private final float matchCost; |
| |
| PhraseMatcher(float matchCost) { |
| this.matchCost = matchCost; |
| } |
| |
| /** |
| * Approximation that only matches documents that have all terms. |
| */ |
| abstract DocIdSetIterator approximation(); |
| |
| /** |
| * Approximation that is aware of impacts. |
| */ |
| abstract ImpactsDISI impactsApproximation(); |
| |
| /** |
| * An upper bound on the number of possible matches on this document |
| */ |
| abstract float maxFreq() throws IOException; |
| |
| /** |
| * Called after {@link #approximation} has been advanced |
| */ |
| public abstract void reset() throws IOException; |
| |
| /** |
| * Find the next match on the current document, returning {@code false} if there |
| * are none. |
| */ |
| public abstract boolean nextMatch() throws IOException; |
| |
| /** |
| * The slop-adjusted weight of the current match |
| * |
| * The sum of the slop-adjusted weights is used as the freq for scoring |
| */ |
| abstract float sloppyWeight(); |
| |
| /** |
| * The start position of the current match |
| */ |
| abstract int startPosition(); |
| |
| /** |
| * The end position of the current match |
| */ |
| abstract int endPosition(); |
| |
| /** |
| * The start offset of the current match |
| */ |
| abstract int startOffset() throws IOException; |
| |
| /** |
| * The end offset of the current match |
| */ |
| abstract int endOffset() throws IOException; |
| |
| /** |
| * An estimate of the average cost of finding all matches on a document |
| * |
| * @see TwoPhaseIterator#matchCost() |
| */ |
| public float getMatchCost() { |
| return matchCost; |
| } |
| |
| } |