opennlp.tools.namefind.BilouCodec Maven / Gradle / Ivy
/*
* 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.namefind;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import opennlp.tools.util.SequenceCodec;
import opennlp.tools.util.SequenceValidator;
import opennlp.tools.util.Span;
public class BilouCodec implements SequenceCodec {
public static final String START = "start";
public static final String CONTINUE = "cont";
public static final String LAST = "last";
public static final String UNIT = "unit";
public static final String OTHER = "other";
@Override
public Span[] decode(List c) {
int start = -1;
int end = -1;
List spans = new ArrayList<>(c.size());
for (int li = 0; li < c.size(); li++) {
String chunkTag = c.get(li);
if (chunkTag.endsWith(BilouCodec.START)) {
start = li;
end = li + 1;
}
else if (chunkTag.endsWith(BilouCodec.CONTINUE)) {
end = li + 1;
}
else if (chunkTag.endsWith(LAST)) {
if (start != -1) {
spans.add(new Span(start, end + 1, BioCodec.extractNameType(c.get(li - 1))));
start = -1;
end = -1;
}
}
else if (chunkTag.endsWith(UNIT)) {
spans.add(new Span(li, li + 1, BioCodec.extractNameType(c.get(li))));
}
}
return spans.toArray(new Span[spans.size()]);
}
@Override
public String[] encode(Span[] names, int length) {
String[] outcomes = new String[length];
Arrays.fill(outcomes, BilouCodec.OTHER);
for (Span name : names) {
if (name.length() > 1) {
if (name.getType() == null) {
outcomes[name.getStart()] = "default" + "-" + BilouCodec.START;
}
else {
outcomes[name.getStart()] = name.getType() + "-" + BilouCodec.START;
}
// now iterate from begin + 1 till end
for (int i = name.getStart() + 1; i < name.getEnd() - 1; i++) {
if (name.getType() == null) {
outcomes[i] = "default" + "-" + BilouCodec.CONTINUE;
}
else {
outcomes[i] = name.getType() + "-" + BilouCodec.CONTINUE;
}
}
if (name.getType() == null) {
outcomes[name.getEnd() - 1] = "default" + "-" + BilouCodec.LAST;
}
else {
outcomes[name.getEnd() - 1] = name.getType() + "-" + BilouCodec.LAST;
}
}
else {
if (name.getType() == null) {
outcomes[name.getEnd() - 1] = "default" + "-" + BilouCodec.UNIT;
}
else {
outcomes[name.getEnd() - 1] = name.getType() + "-" + BilouCodec.UNIT;
}
}
}
return outcomes;
}
@Override
public SequenceValidator createSequenceValidator() {
return new BilouNameFinderSequenceValidator();
}
/**
* B requires CL or L
* C requires BL
* L requires B
* O requires any valid combo/unit
* U requires none
*
* @param outcomes all possible model outcomes
*
* @return true, if model outcomes are compatible
*/
@Override
public boolean areOutcomesCompatible(String[] outcomes) {
Set start = new HashSet<>();
Set cont = new HashSet<>();
Set last = new HashSet<>();
Set unit = new HashSet<>();
for (int i = 0; i < outcomes.length; i++) {
String outcome = outcomes[i];
if (outcome.endsWith(BilouCodec.START)) {
start.add(outcome.substring(0, outcome.length()
- BilouCodec.START.length()));
} else if (outcome.endsWith(BilouCodec.CONTINUE)) {
cont.add(outcome.substring(0, outcome.length()
- BilouCodec.CONTINUE.length()));
} else if (outcome.endsWith(BilouCodec.LAST)) {
last.add(outcome.substring(0, outcome.length()
- BilouCodec.LAST.length()));
} else if (outcome.endsWith(BilouCodec.UNIT)) {
unit.add(outcome.substring(0, outcome.length()
- BilouCodec.UNIT.length()));
} else if (!outcome.equals(BilouCodec.OTHER)) {
return false;
}
}
if (start.size() == 0 && unit.size() == 0) {
return false;
} else {
// Start, must have matching Last
for (String startPrefix : start) {
if (!last.contains(startPrefix)) {
return false;
}
}
// Cont, must have matching Start and Last
for (String contPrefix : cont) {
if (!start.contains(contPrefix) && !last.contains(contPrefix)) {
return false;
}
}
// Last, must have matching Start
for (String lastPrefix : last) {
if (!start.contains(lastPrefix)) {
return false;
}
}
}
return true;
}
}