1 package org.apache.lucene.search;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
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20 import java.io.IOException;
22 import org.apache.lucene.index.IndexReader;
23 import org.apache.lucene.index.Term;
25 abstract class TermCollectingRewrite<Q extends Query> extends MultiTermQuery.RewriteMethod {
27 /** Return a suitable top-level Query for holding all expanded terms. */
28 protected abstract Q getTopLevelQuery() throws IOException;
30 /** Add a MultiTermQuery term to the top-level query */
31 protected abstract void addClause(Q topLevel, Term term, float boost) throws IOException;
33 protected final void collectTerms(IndexReader reader, MultiTermQuery query, TermCollector collector) throws IOException {
34 final FilteredTermEnum enumerator = query.getEnum(reader);
37 final Term t = enumerator.term();
38 if (t == null || !collector.collect(t, enumerator.difference()))
40 } while (enumerator.next());
46 protected interface TermCollector {
47 /** return false to stop collecting */
48 boolean collect(Term t, float boost) throws IOException;