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lucene 4: remove Pattern tokenizer and filter

This commit is contained in:
Igor Motov 2012-10-26 00:03:16 -04:00 committed by Shay Banon
parent 097cb2dac7
commit 6fad75df82
2 changed files with 0 additions and 238 deletions
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85
src/main/java/org/apache/lucene/analysis/pattern/PatternReplaceFilter.java
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/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch 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.analysis.pattern;
import org.apache.lucene.analysis.TokenFilter;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* A TokenFilter which applies a Pattern to each token in the stream,
* replacing match occurances with the specified replacement string.
* <p/>
* <p>
* <b>Note:</b> Depending on the input and the pattern used and the input
* TokenStream, this TokenFilter may produce Tokens whose text is the empty
* string.
* </p>
*
* @see Pattern
*/
public final class PatternReplaceFilter extends TokenFilter {
private final Pattern p;
private final String replacement;
private final boolean all;
private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
private final Matcher m;
/**
* Constructs an instance to replace either the first, or all occurances
*
* @param in the TokenStream to process
* @param p the patterm to apply to each Token
* @param replacement the "replacement string" to substitute, if null a
* blank string will be used. Note that this is not the literal
* string that will be used, '$' and '\' have special meaning.
* @param all if true, all matches will be replaced otherwise just the first match.
* @see Matcher#quoteReplacement
*/
public PatternReplaceFilter(TokenStream in,
Pattern p,
String replacement,
boolean all) {
super(in);
this.p = p;
this.replacement = (null == replacement) ? "" : replacement;
this.all = all;
this.m = p.matcher(termAtt);
}
@Override
public boolean incrementToken() throws IOException {
if (!input.incrementToken()) return false;
m.reset();
if (m.find()) {
// replaceAll/replaceFirst will reset() this previous find.
String transformed = all ? m.replaceAll(replacement) : m.replaceFirst(replacement);
termAtt.setEmpty().append(transformed);
}
return true;
}
}

153
src/main/java/org/apache/lucene/analysis/pattern/PatternTokenizer.java
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@ -1,153 +0,0 @@
/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch 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.analysis.pattern;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
import java.io.IOException;
import java.io.Reader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* This tokenizer uses regex pattern matching to construct distinct tokens
* for the input stream. It takes two arguments: "pattern" and "group".
* <p/>
* <ul>
* <li>"pattern" is the regular expression.</li>
* <li>"group" says which group to extract into tokens.</li>
* </ul>
* <p>
* group=-1 (the default) is equivalent to "split". In this case, the tokens will
* be equivalent to the output from (without empty tokens):
* {@link String#split(java.lang.String)}
* </p>
* <p>
* Using group >= 0 selects the matching group as the token. For example, if you have:<br/>
* <pre>
* pattern = \'([^\']+)\'
* group = 0
* input = aaa 'bbb' 'ccc'
* </pre>
* the output will be two tokens: 'bbb' and 'ccc' (including the ' marks). With the same input
* but using group=1, the output would be: bbb and ccc (no ' marks)
* </p>
* <p>NOTE: This Tokenizer does not output tokens that are of zero length.</p>
*
* @see Pattern
*/
public final class PatternTokenizer extends Tokenizer {
private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
private final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
private final StringBuilder str = new StringBuilder();
private int index;
private final Pattern pattern;
private final int group;
private final Matcher matcher;
/**
* creates a new PatternTokenizer returning tokens from group (-1 for split functionality)
*/
public PatternTokenizer(Reader input, Pattern pattern, int group) throws IOException {
super(input);
this.pattern = pattern;
this.group = group;
fillBuffer(str, input);
matcher = pattern.matcher(str);
index = 0;
}
@Override
public boolean incrementToken() throws IOException {
if (index >= str.length()) return false;
clearAttributes();
if (group >= 0) {
// match a specific group
while (matcher.find()) {
index = matcher.start(group);
final int endIndex = matcher.end(group);
if (index == endIndex) continue;
termAtt.setEmpty().append(str, index, endIndex);
offsetAtt.setOffset(correctOffset(index), correctOffset(endIndex));
return true;
}
index = Integer.MAX_VALUE; // mark exhausted
return false;
} else {
// String.split() functionality
while (matcher.find()) {
if (matcher.start() - index > 0) {
// found a non-zero-length token
termAtt.setEmpty().append(str, index, matcher.start());
offsetAtt.setOffset(correctOffset(index), correctOffset(matcher.start()));
index = matcher.end();
return true;
}
index = matcher.end();
}
if (str.length() - index == 0) {
index = Integer.MAX_VALUE; // mark exhausted
return false;
}
termAtt.setEmpty().append(str, index, str.length());
offsetAtt.setOffset(correctOffset(index), correctOffset(str.length()));
index = Integer.MAX_VALUE; // mark exhausted
return true;
}
}
@Override
public void end() throws IOException {
final int ofs = correctOffset(str.length());
offsetAtt.setOffset(ofs, ofs);
}
@Override
public void reset(Reader input) throws IOException {
super.reset(input);
fillBuffer(str, input);
matcher.reset(str);
index = 0;
}
// TODO: we should see if we can make this tokenizer work without reading
// the entire document into RAM, perhaps with Matcher.hitEnd/requireEnd ?
final char[] buffer = new char[8192];
private void fillBuffer(StringBuilder sb, Reader input) throws IOException {
int len;
sb.setLength(0);
while ((len = input.read(buffer)) > 0) {
sb.append(buffer, 0, len);
}
}
}