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Stanford Parser processes raw text in English, Chinese, German, Arabic, and French, and extracts constituency parse trees.
package edu.stanford.nlp.international.arabic;
import edu.stanford.nlp.util.logging.Redwood;
import java.io.*;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import edu.stanford.nlp.international.morph.MorphoFeatureSpecification;
import edu.stanford.nlp.international.morph.MorphoFeatures;
/**
* Extracts morphosyntactic features from BAMA/SAMA analyses. Compatible with both the
* long tags in the ATB and the output of MADA.
*
* @author Spence Green
*
*/
public class ArabicMorphoFeatureSpecification extends MorphoFeatureSpecification {
/** A logger for this class */
private static Redwood.RedwoodChannels log = Redwood.channels(ArabicMorphoFeatureSpecification.class);
private static final long serialVersionUID = 4448045447200922076L;
private static final String[] defVals = {"I", "D"};
private static final String[] caseVals = {"NOM","ACC","GEN"};
private static final String[] genVals = {"M","F"};
private static final String[] numVals = {"SG","DU","PL"};
private static final String[] perVals = {"1","2","3"};
private static final String[] possVals = {"POSS"};
private static final String[] voiceVals = {"ACT","PASS"};
private static final String[] moodVals = {"I","S","J"};
private static final String[] tenseVals = {"PAST","PRES","IMP"};
// Standard feature tuple (e.g., "3MS", "1P", etc.)
private static final Pattern pFeatureTuple = Pattern.compile("(\\d\\p{Upper}\\p{Upper}?)");
// Demonstrative pronouns do not have number
private static final Pattern pDemPronounFeatures = Pattern.compile("DEM_PRON(.+)");
//Verbal patterns
private static final Pattern pVerbMood = Pattern.compile("MOOD|SUBJ");
private static final Pattern pMood = Pattern.compile("_MOOD:([ISJ])");
private static final Pattern pVerbTenseMarker = Pattern.compile("IV|PV|CV");
private static final Pattern pNounNoMorph = Pattern.compile("PROP|QUANT");
@Override
public List getValues(MorphoFeatureType feat) {
if(feat == MorphoFeatureType.DEF)
return Arrays.asList(defVals);
else if(feat == MorphoFeatureType.CASE) {
throw new RuntimeException(this.getClass().getName() + ": Case is presently unsupported!");
// return Arrays.asList(caseVals);
} else if(feat == MorphoFeatureType.GEN)
return Arrays.asList(genVals);
else if(feat == MorphoFeatureType.NUM)
return Arrays.asList(numVals);
else if(feat == MorphoFeatureType.PER)
return Arrays.asList(perVals);
else if(feat == MorphoFeatureType.POSS)
return Arrays.asList(possVals);
else if(feat == MorphoFeatureType.VOICE)
return Arrays.asList(voiceVals);
else if(feat == MorphoFeatureType.MOOD)
return Arrays.asList(moodVals);
else if(feat == MorphoFeatureType.TENSE)
return Arrays.asList(tenseVals);
else
throw new IllegalArgumentException("Arabic does not support feature type: " + feat.toString());
}
/**
* Hand-written rules to convert SAMA analyses to feature structures.
*/
@Override
public MorphoFeatures strToFeatures(String spec) {
MorphoFeatures features = new ArabicMorphoFeatures();
// Check for the boundary symbol
if(spec == null || spec.equals("")) {
return features;
}
//Possessiveness
if(isActive(MorphoFeatureType.POSS) && spec.contains("POSS")) {
features.addFeature(MorphoFeatureType.POSS,possVals[0]);
}
//Nominals and pronominals. Mona ignores Pronominals in ERTS, but they seem to help...
// NSUFF -- declinable nominals
// VSUFF -- enclitic pronominals
// PRON -- ordinary pronominals
if(spec.contains("NSUFF") || spec.contains("NOUN") || spec.contains("ADJ")) {
// Nominal phi feature indicators are different than the indicators
// that we process with processInflectionalFeatures()
if(isActive(MorphoFeatureType.NGEN)) {
if(spec.contains("FEM")) {
features.addFeature(MorphoFeatureType.NGEN, genVals[1]);
} else if(spec.contains("MASC") || !pNounNoMorph.matcher(spec).find()) {
features.addFeature(MorphoFeatureType.NGEN, genVals[0]);
}
}
// WSGDEBUG -- Number for nominals only
if(isActive(MorphoFeatureType.NNUM)) {
if(spec.contains("DU")) {
features.addFeature(MorphoFeatureType.NNUM, numVals[1]);
} else if(spec.contains("PL")) {
features.addFeature(MorphoFeatureType.NNUM, numVals[2]);
} else if (!pNounNoMorph.matcher(spec).find()){ // (spec.contains("SG"))
features.addFeature(MorphoFeatureType.NNUM, numVals[0]);
}
}
//Definiteness
if(isActive(MorphoFeatureType.DEF)) {
if (spec.contains("DET")) {
features.addFeature(MorphoFeatureType.DEF, defVals[1]);
} else if (!pNounNoMorph.matcher(spec).find()){
features.addFeature(MorphoFeatureType.DEF, defVals[0]);
}
}
// Proper nouns (probably a stupid feature)
if (isActive(MorphoFeatureType.PROP)) {
if (spec.contains("PROP")) {
features.addFeature(MorphoFeatureType.PROP,"");
}
}
} else if(spec.contains("PRON") || (spec.contains("VSUFF_DO") && !pVerbMood.matcher(spec).find())) {
if(spec.contains("DEM_PRON")) {
features.addFeature(MorphoFeatureType.DEF, defVals[0]);
Matcher m = pDemPronounFeatures.matcher(spec);
if (m.find()) {
spec = m.group(1);
processInflectionalFeaturesHelper(features, spec);
}
} else {
processInflectionalFeatures(features, spec);
}
// Verbs (marked for tense)
} else if(pVerbTenseMarker.matcher(spec).find()) {
// Tense feature
if(isActive(MorphoFeatureType.TENSE)) {
if(spec.contains("PV"))
features.addFeature(MorphoFeatureType.TENSE, tenseVals[0]);
else if(spec.contains("IV"))
features.addFeature(MorphoFeatureType.TENSE, tenseVals[1]);
else if(spec.contains("CV"))
features.addFeature(MorphoFeatureType.TENSE, tenseVals[2]);
}
// Inflectional features
processInflectionalFeatures(features, spec);
if(isActive(MorphoFeatureType.MOOD)) {
Matcher moodMatcher = pMood.matcher(spec);
if(moodMatcher.find()) {
String moodStr = moodMatcher.group(1);
switch (moodStr) {
case "I":
features.addFeature(MorphoFeatureType.MOOD, moodVals[0]);
break;
case "S":
features.addFeature(MorphoFeatureType.MOOD, moodVals[1]);
break;
case "J":
features.addFeature(MorphoFeatureType.MOOD, moodVals[2]);
break;
}
}
}
if(isActive(MorphoFeatureType.VOICE)) {
if(spec.contains("PASS")) {
features.addFeature(MorphoFeatureType.VOICE, voiceVals[1]);
} else {
features.addFeature(MorphoFeatureType.VOICE, voiceVals[0]);
}
}
}
return features;
}
/**
* Extract features from a standard phi feature specification.
*
* @param feats
* @param spec
*/
private void processInflectionalFeatures(MorphoFeatures feats, String spec) {
// Extract the feature tuple
Matcher m = pFeatureTuple.matcher(spec);
if (m.find()) {
spec = m.group(1);
processInflectionalFeaturesHelper(feats, spec);
}
}
private void processInflectionalFeaturesHelper(MorphoFeatures feats, String spec) {
if(isActive(MorphoFeatureType.GEN)) {
if(spec.contains("M"))
feats.addFeature(MorphoFeatureType.GEN, genVals[0]);
else if(spec.contains("F"))
feats.addFeature(MorphoFeatureType.GEN, genVals[1]);
}
if(isActive(MorphoFeatureType.NUM)) {
if(spec.endsWith("S"))
feats.addFeature(MorphoFeatureType.NUM, numVals[0]);
else if(spec.endsWith("D"))
feats.addFeature(MorphoFeatureType.NUM, numVals[1]);
else if(spec.endsWith("P"))
feats.addFeature(MorphoFeatureType.NUM, numVals[2]);
}
if(isActive(MorphoFeatureType.PER)) {
if(spec.contains("1"))
feats.addFeature(MorphoFeatureType.PER, perVals[0]);
else if(spec.contains("2"))
feats.addFeature(MorphoFeatureType.PER, perVals[1]);
else if(spec.contains("3"))
feats.addFeature(MorphoFeatureType.PER, perVals[2]);
}
}
/**
* Converts features specifications to labels for tagging
*
* @author Spence Green
*
*/
public static class ArabicMorphoFeatures extends MorphoFeatures {
private static final long serialVersionUID = -4611776415583633186L;
@Override
public MorphoFeatures fromTagString(String str) {
String[] feats = str.split("\\-");
MorphoFeatures mFeats = new ArabicMorphoFeatures();
// First element is the base POS
// String baseTag = feats[0];
for(int i = 1; i < feats.length; i++) {
String[] keyValue = feats[i].split(KEY_VAL_DELIM);
if(keyValue.length != 2) continue;
MorphoFeatureType fName = MorphoFeatureType.valueOf(keyValue[0].trim());
mFeats.addFeature(fName, keyValue[1].trim());
}
return mFeats;
}
@Override
public String getTag(String basePartOfSpeech) {
StringBuilder sb = new StringBuilder(basePartOfSpeech);
// Iterate over feature list so that features are added in the same order
// for every feature spec.
for (MorphoFeatureType feat : MorphoFeatureType.values()) {
if (hasFeature(feat)) {
sb.append(String.format("-%s:%s",feat,fSpec.get(feat)));
}
}
return sb.toString();
}
}
/**
* For debugging. Converts a set of long tags (BAMA analyses as in the ATB) to their morpho
* feature specification. The input file should have one long tag per line.
*
* @param args
*/
public static void main(String[] args) {
if(args.length != 2) {
System.err.printf("Usage: java %s filename feats%n", ArabicMorphoFeatureSpecification.class.getName());
System.exit(-1);
}
MorphoFeatureSpecification fSpec = new ArabicMorphoFeatureSpecification();
String[] feats = args[1].split(",");
for(String feat : feats) {
MorphoFeatureType fType = MorphoFeatureType.valueOf(feat);
fSpec.activate(fType);
}
File fName = new File(args[0]);
try {
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(fName)));
int nLine = 0;
for(String line;(line = br.readLine()) != null; nLine++) {
MorphoFeatures mFeats = fSpec.strToFeatures(line.trim());
System.out.printf("%s\t%s%n", line.trim(), mFeats.toString());
}
br.close();
System.out.printf("%nRead %d lines%n",nLine);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}