/*
* 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 opennlp.tools.formats.ad;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import opennlp.tools.chunker.ChunkSample;
import opennlp.tools.formats.ad.ADSentenceStream.Sentence;
import opennlp.tools.formats.ad.ADSentenceStream.SentenceParser.Leaf;
import opennlp.tools.formats.ad.ADSentenceStream.SentenceParser.Node;
import opennlp.tools.formats.ad.ADSentenceStream.SentenceParser.TreeElement;
import opennlp.tools.namefind.NameSample;
import opennlp.tools.util.ObjectStream;
import opennlp.tools.util.PlainTextByLineStream;
/**
* Parser for Floresta Sita(c)tica Arvores Deitadas corpus, output to for the
* Portuguese Chunker training.
* <p>
* The heuristic to extract chunks where based o paper 'A Machine Learning
* Approach to Portuguese Clause Identification', (Eraldo Fernandes, Cicero
* Santos and Ruy Milidiú).<br>
* <p>
* Data can be found on this web site:<br>
* http://www.linguateca.pt/floresta/corpus.html
* <p>
* Information about the format:<br>
* Susana Afonso.
* "Árvores deitadas: Descrição do formato e das opções de análise na Floresta Sintáctica"
* .<br>
* 12 de Fevereiro de 2006.
* http://www.linguateca.pt/documentos/Afonso2006ArvoresDeitadas.pdf
* <p>
* Detailed info about the NER tagset:
* http://beta.visl.sdu.dk/visl/pt/info/portsymbol.html#semtags_names
* <p>
* <b>Note:</b> Do not use this class, internal use only!
*/
public class ADChunkSampleStream implements ObjectStream<ChunkSample> {
protected final ObjectStream<ADSentenceStream.Sentence> adSentenceStream;
private int start = -1;
private int end = -1;
private int index = 0;
public static final String OTHER = "O";
/**
* Creates a new {@link NameSample} stream from a line stream, i.e.
* {@link ObjectStream}< {@link String}>, that could be a
* {@link PlainTextByLineStream} object.
*
* @param lineStream
* a stream of lines as {@link String}
*/
public ADChunkSampleStream(ObjectStream<String> lineStream) {
this.adSentenceStream = new ADSentenceStream(lineStream);
}
/**
* Creates a new {@link NameSample} stream from a {@link InputStream}
*
* @param in
* the Corpus {@link InputStream}
* @param charsetName
* the charset of the Arvores Deitadas Corpus
*/
public ADChunkSampleStream(InputStream in, String charsetName) {
try {
this.adSentenceStream = new ADSentenceStream(new PlainTextByLineStream(
in, charsetName));
} catch (UnsupportedEncodingException e) {
// UTF-8 is available on all JVMs, will never happen
throw new IllegalStateException(e);
}
}
public ChunkSample read() throws IOException {
Sentence paragraph;
while ((paragraph = this.adSentenceStream.read()) != null) {
if (end > -1 && index >= end) {
// leave
return null;
}
if (start > -1 && index < start) {
index++;
// skip this one
} else {
Node root = paragraph.getRoot();
List<String> sentence = new ArrayList<String>();
List<String> tags = new ArrayList<String>();
List<String> target = new ArrayList<String>();
processRoot(root, sentence, tags, target);
if (sentence.size() > 0) {
index++;
return new ChunkSample(sentence, tags, target);
}
}
}
return null;
}
protected void processRoot(Node root, List<String> sentence, List<String> tags,
List<String> target) {
if (root != null) {
TreeElement[] elements = root.getElements();
for (int i = 0; i < elements.length; i++) {
if (elements[i].isLeaf()) {
processLeaf((Leaf) elements[i], false, OTHER, sentence, tags, target);
} else {
processNode((Node) elements[i], sentence, tags, target, null);
}
}
}
}
private void processNode(Node node, List<String> sentence, List<String> tags,
List<String> target, String inheritedTag) {
String phraseTag = getChunkTag(node);
boolean inherited = false;
if(phraseTag.equals(OTHER) && inheritedTag != null) {
phraseTag = inheritedTag;
inherited = true;
}
TreeElement[] elements = node.getElements();
for (int i = 0; i < elements.length; i++) {
if (elements[i].isLeaf()) {
boolean isIntermediate = false;
String tag = phraseTag;
Leaf leaf = (Leaf) elements[i];
String localChunk = getChunkTag(leaf);
if(localChunk != null && !tag.equals(localChunk)) {
tag = localChunk;
}
if(isIntermediate(tags, target, tag) && (inherited || i > 0)) {
isIntermediate = true;
}
if(!isIncludePunctuations() && leaf.getFunctionalTag() == null &&
(
!( i + 1 < elements.length && elements[i+1].isLeaf() ) ||
!( i > 0 && elements[i - 1].isLeaf() )
)
){
isIntermediate = false;
tag = OTHER;
}
processLeaf(leaf, isIntermediate, tag, sentence,
tags, target);
} else {
int before = target.size();
processNode((Node) elements[i], sentence, tags, target, phraseTag);
// if the child node was of a different type we should break the chunk sequence
for (int j = target.size() - 1; j >= before; j--) {
if(!target.get(j).endsWith("-" + phraseTag)) {
phraseTag = OTHER;
break;
}
}
}
}
}
protected void processLeaf(Leaf leaf, boolean isIntermediate, String phraseTag,
List<String> sentence, List<String> tags, List<String> target) {
String chunkTag;
if (leaf.getFunctionalTag() != null
&& phraseTag.equals(OTHER)) {
phraseTag = getPhraseTagFromPosTag(leaf.getFunctionalTag());
}
if (!phraseTag.equals(OTHER)) {
if (isIntermediate) {
chunkTag = "I-" + phraseTag;
} else {
chunkTag = "B-" + phraseTag;
}
} else {
chunkTag = phraseTag;
}
sentence.add(leaf.getLexeme());
if (leaf.getSyntacticTag() == null) {
tags.add(leaf.getLexeme());
} else {
tags.add(ADChunkSampleStream.convertFuncTag(leaf.getFunctionalTag(), false));
}
target.add(chunkTag);
}
protected String getPhraseTagFromPosTag(String functionalTag) {
if (functionalTag.equals("v-fin")) {
return "VP";
} else if (functionalTag.equals("n")) {
return "NP";
}
return OTHER;
}
public static String convertFuncTag(String t, boolean useCGTags) {
if (useCGTags) {
if ("art".equals(t) || "pron-det".equals(t) || "pron-indef".equals(t)) {
t = "det";
}
}
return t;
}
protected String getChunkTag(Leaf leaf) {
String tag = leaf.getSyntacticTag();
if("P".equals(tag)) {
return "VP";
}
return null;
}
protected String getChunkTag(Node node) {
String tag = node.getSyntacticTag();
String phraseTag = tag.substring(tag.lastIndexOf(":") + 1);
while (phraseTag.endsWith("-")) {
phraseTag = phraseTag.substring(0, phraseTag.length() - 1);
}
// maybe we should use only np, vp and pp, but will keep ap and advp.
if (phraseTag.equals("np") || phraseTag.equals("vp")
|| phraseTag.equals("pp") || phraseTag.equals("ap")
|| phraseTag.equals("advp") || phraseTag.equals("adjp")) {
phraseTag = phraseTag.toUpperCase();
} else {
phraseTag = OTHER;
}
return phraseTag;
}
public void setStart(int aStart) {
this.start = aStart;
}
public void setEnd(int aEnd) {
this.end = aEnd;
}
public void reset() throws IOException, UnsupportedOperationException {
adSentenceStream.reset();
}
public void close() throws IOException {
adSentenceStream.close();
}
protected boolean isIncludePunctuations() {
return false;
}
protected boolean isIntermediate(List<String> tags, List<String> target,
String phraseTag) {
return target.size() > 0
&& target.get(target.size() - 1).endsWith("-" + phraseTag);
}
}