--- /dev/null
+package org.apache.lucene.analysis.compound;
+
+/**
+ * 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.
+ */
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.Locale;
+import java.util.Set;
+
+import org.apache.lucene.analysis.CharArraySet;
+import org.apache.lucene.analysis.TokenFilter;
+import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
+import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
+import org.apache.lucene.util.AttributeSource;
+import org.apache.lucene.util.Version;
+
+/**
+ * Base class for decomposition token filters.
+ * <p>
+ * You must specify the required {@link Version} compatibility when creating
+ * CompoundWordTokenFilterBase:
+ * <ul>
+ * <li>As of 3.1, CompoundWordTokenFilterBase correctly handles Unicode 4.0
+ * supplementary characters in strings and char arrays provided as compound word
+ * dictionaries.
+ * </ul>
+ * <p>If you pass in a {@link org.apache.lucene.analysis.CharArraySet} as dictionary,
+ * it should be case-insensitive unless it contains only lowercased entries and you
+ * have {@link org.apache.lucene.analysis.LowerCaseFilter} before this filter in your analysis chain.
+ * For optional performance (as this filter does lots of lookups to the dictionary,
+ * you should use the latter analysis chain/CharArraySet). Be aware: If you supply arbitrary
+ * {@link Set Sets} to the ctors or {@code String[]} dictionaries, they will be automatically
+ * transformed to case-insensitive!
+ */
+public abstract class CompoundWordTokenFilterBase extends TokenFilter {
+ /**
+ * The default for minimal word length that gets decomposed
+ */
+ public static final int DEFAULT_MIN_WORD_SIZE = 5;
+
+ /**
+ * The default for minimal length of subwords that get propagated to the output of this filter
+ */
+ public static final int DEFAULT_MIN_SUBWORD_SIZE = 2;
+
+ /**
+ * The default for maximal length of subwords that get propagated to the output of this filter
+ */
+ public static final int DEFAULT_MAX_SUBWORD_SIZE = 15;
+
+ protected final CharArraySet dictionary;
+ protected final LinkedList<CompoundToken> tokens;
+ protected final int minWordSize;
+ protected final int minSubwordSize;
+ protected final int maxSubwordSize;
+ protected final boolean onlyLongestMatch;
+
+ protected final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
+ protected final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
+ private final PositionIncrementAttribute posIncAtt = addAttribute(PositionIncrementAttribute.class);
+
+ private AttributeSource.State current;
+
+ /**
+ * @deprecated use {@link #CompoundWordTokenFilterBase(Version, TokenStream, String[], int, int, int, boolean)} instead
+ */
+ @Deprecated
+ protected CompoundWordTokenFilterBase(TokenStream input, String[] dictionary, int minWordSize, int minSubwordSize, int maxSubwordSize, boolean onlyLongestMatch) {
+ this(Version.LUCENE_30, input, makeDictionary(Version.LUCENE_30, dictionary),minWordSize,minSubwordSize,maxSubwordSize, onlyLongestMatch);
+ }
+
+ /**
+ * @deprecated use {@link #CompoundWordTokenFilterBase(Version, TokenStream, String[], boolean)} instead
+ */
+ @Deprecated
+ protected CompoundWordTokenFilterBase(TokenStream input, String[] dictionary, boolean onlyLongestMatch) {
+ this(Version.LUCENE_30, input, makeDictionary(Version.LUCENE_30, dictionary),DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, onlyLongestMatch);
+ }
+
+ /**
+ * @deprecated use {@link #CompoundWordTokenFilterBase(Version, TokenStream, Set, boolean)} instead
+ */
+ @Deprecated
+ protected CompoundWordTokenFilterBase(TokenStream input, Set<?> dictionary, boolean onlyLongestMatch) {
+ this(Version.LUCENE_30, input, dictionary,DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, onlyLongestMatch);
+ }
+
+ /**
+ * @deprecated use {@link #CompoundWordTokenFilterBase(Version, TokenStream, String[])} instead
+ */
+ @Deprecated
+ protected CompoundWordTokenFilterBase(TokenStream input, String[] dictionary) {
+ this(Version.LUCENE_30, input, makeDictionary(Version.LUCENE_30, dictionary),DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, false);
+ }
+
+ /**
+ * @deprecated use {@link #CompoundWordTokenFilterBase(Version, TokenStream, Set)} instead
+ */
+ @Deprecated
+ protected CompoundWordTokenFilterBase(TokenStream input, Set<?> dictionary) {
+ this(Version.LUCENE_30, input, dictionary,DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, false);
+ }
+
+ /**
+ * @deprecated use {@link #CompoundWordTokenFilterBase(Version, TokenStream, Set, int, int, int, boolean)} instead
+ */
+ @Deprecated
+ protected CompoundWordTokenFilterBase(TokenStream input, Set<?> dictionary, int minWordSize, int minSubwordSize, int maxSubwordSize, boolean onlyLongestMatch) {
+ this(Version.LUCENE_30, input, dictionary, minWordSize, minSubwordSize, maxSubwordSize, onlyLongestMatch);
+ }
+
+ protected CompoundWordTokenFilterBase(Version matchVersion, TokenStream input, String[] dictionary, int minWordSize, int minSubwordSize, int maxSubwordSize, boolean onlyLongestMatch) {
+ this(matchVersion, input,makeDictionary(matchVersion, dictionary),minWordSize,minSubwordSize,maxSubwordSize, onlyLongestMatch);
+ }
+
+ protected CompoundWordTokenFilterBase(Version matchVersion, TokenStream input, String[] dictionary, boolean onlyLongestMatch) {
+ this(matchVersion, input,makeDictionary(matchVersion, dictionary),DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, onlyLongestMatch);
+ }
+
+ protected CompoundWordTokenFilterBase(Version matchVersion, TokenStream input, Set<?> dictionary, boolean onlyLongestMatch) {
+ this(matchVersion, input,dictionary,DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, onlyLongestMatch);
+ }
+
+ protected CompoundWordTokenFilterBase(Version matchVersion, TokenStream input, String[] dictionary) {
+ this(matchVersion, input,makeDictionary(matchVersion, dictionary),DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, false);
+ }
+
+ protected CompoundWordTokenFilterBase(Version matchVersion, TokenStream input, Set<?> dictionary) {
+ this(matchVersion, input,dictionary,DEFAULT_MIN_WORD_SIZE,DEFAULT_MIN_SUBWORD_SIZE,DEFAULT_MAX_SUBWORD_SIZE, false);
+ }
+
+ protected CompoundWordTokenFilterBase(Version matchVersion, TokenStream input, Set<?> dictionary, int minWordSize, int minSubwordSize, int maxSubwordSize, boolean onlyLongestMatch) {
+ super(input);
+
+ this.tokens=new LinkedList<CompoundToken>();
+ this.minWordSize=minWordSize;
+ this.minSubwordSize=minSubwordSize;
+ this.maxSubwordSize=maxSubwordSize;
+ this.onlyLongestMatch=onlyLongestMatch;
+
+ if (dictionary==null || dictionary instanceof CharArraySet) {
+ this.dictionary = (CharArraySet) dictionary;
+ } else {
+ this.dictionary = new CharArraySet(matchVersion, dictionary, true);
+ }
+ }
+
+ /** @deprecated Only available for backwards compatibility. */
+ @Deprecated
+ public static CharArraySet makeDictionary(final Version matchVersion, final String[] dictionary) {
+ if (dictionary == null) {
+ return null;
+ }
+ return new CharArraySet(matchVersion, Arrays.asList(dictionary), true);
+ }
+
+ @Override
+ public final boolean incrementToken() throws IOException {
+ if (!tokens.isEmpty()) {
+ assert current != null;
+ CompoundToken token = tokens.removeFirst();
+ restoreState(current); // keep all other attributes untouched
+ termAtt.setEmpty().append(token.txt);
+ offsetAtt.setOffset(token.startOffset, token.endOffset);
+ posIncAtt.setPositionIncrement(0);
+ return true;
+ }
+
+ current = null; // not really needed, but for safety
+ if (input.incrementToken()) {
+ // Only words longer than minWordSize get processed
+ if (termAtt.length() >= this.minWordSize) {
+ decompose();
+ // only capture the state if we really need it for producing new tokens
+ if (!tokens.isEmpty()) {
+ current = captureState();
+ }
+ }
+ // return original token:
+ return true;
+ } else {
+ return false;
+ }
+ }
+
+ /** Decomposes the current {@link #termAtt} and places {@link CompoundToken} instances in the {@link #tokens} list.
+ * The original token may not be placed in the list, as it is automatically passed through this filter.
+ */
+ protected abstract void decompose();
+
+ @Override
+ public void reset() throws IOException {
+ super.reset();
+ tokens.clear();
+ current = null;
+ }
+
+ /**
+ * Helper class to hold decompounded token information
+ */
+ protected class CompoundToken {
+ public final CharSequence txt;
+ public final int startOffset, endOffset;
+
+ /** Construct the compound token based on a slice of the current {@link CompoundWordTokenFilterBase#termAtt}. */
+ public CompoundToken(int offset, int length) {
+ final int newStart = CompoundWordTokenFilterBase.this.offsetAtt.startOffset() + offset;
+ this.txt = CompoundWordTokenFilterBase.this.termAtt.subSequence(offset, offset + length);
+ // TODO: This ignores the original endOffset, if a CharFilter/Tokenizer/Filter removed
+ // chars from the term, offsets may not match correctly (other filters producing tokens
+ // may also have this problem):
+ this.startOffset = newStart;
+ this.endOffset = newStart + length;
+ }
+
+ }
+}
fnp / pylucene.git / blobdiff