danbikel.parser.lang
Class AbstractWordFeatures

java.lang.Object
  danbikel.parser.lang.AbstractWordFeatures

All Implemented Interfaces:

WordFeatures, Serializable

Direct Known Subclasses:

SimpleWordFeatures, SimpleWordFeatures, SimpleWordFeatures, WordFeatures, WordFeatures

public abstract class AbstractWordFeatures
extends Object
implements WordFeatures, Serializable

Provides a default abstract implementation of the WordFeatures interface.

See Also:

Serialized Form

Field Summary

protected static Symbol

unknownWordSym The unique symbol to represent unknown words.

Constructor Summary

protected

AbstractWordFeatures() Default constructor, to be called by subclasses (usually implicitly).

Method Summary

abstract Symbol	defaultFeatureVector() The symbol that represents the case where none of the features fires for a particular word.
Symbol	features(Symbol word, boolean firstWord) Returns a symbol representing the orthographic and/or morphological features of the specified word.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

unknownWordSym

protected static Symbol unknownWordSym

The unique symbol to represent unknown words. The default value is the return value of Symbol.add("+unknown+"); if this maps to an actual word in a particular language or Treebank, this data member should be reassigned in a subclass.

Constructor Detail

AbstractWordFeatures

protected AbstractWordFeatures()

Default constructor, to be called by subclasses (usually implicitly).

Method Detail

features

public Symbol features(Symbol word,
                       boolean firstWord)

Returns a symbol representing the orthographic and/or morphological features of the specified word. This default implementation simply returns the unknown word symbol.

Specified by:

features in interface WordFeatures

Parameters:

word - the word whose features are to be computed

firstWord - whether word is the first word in the sentence (useful when computing capitalization features for certain languages, such as English)

Returns:

a symbol representing the orthographic and/or morphological features of word

See Also:

unknownWordSym

defaultFeatureVector

public abstract Symbol defaultFeatureVector()

The symbol that represents the case where none of the features fires for a particular word.

Specified by:

defaultFeatureVector in interface WordFeatures