edu.mit.jwi.morph

Class StemmingRule

java.lang.Object

edu.mit.jwi.morph.StemmingRule

All Implemented Interfaces:

IHasPOS, IStemmingRule

public class StemmingRule
extends Object
implements IStemmingRule

Default implementation of the IStemmingRule interface.

Since:

JWI 2.3.1

Version:

2.4.0

Author:

Mark A. Finlayson

Constructor Summary

Constructors

Constructor and Description
StemmingRule(String suffix, String ending, POS pos, String... ignore) Creates a new stemming rule with the specified suffix, ending, and avoid set

Method Summary

Modifier and Type	Method and Description
String	apply(String word) Applies this rule to the given word.
String	apply(String word, String suffix) Applies this rule to the given word, adding the specified suffix to the end of the returned string.
String	getEnding() Returns the ending for this rule.
POS	getPOS() Returns the associated part of speech for this object.
String	getSuffix() Returns the suffix for this rule.
Set<String>	getSuffixIgnoreSet() Returns the set of suffixes that should be ignored when applying this stemming rule.

Methods inherited from class java.lang.Object

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

Constructor Detail

StemmingRule

public StemmingRule(String suffix,
                    String ending,
                    POS pos,
                    String... ignore)

Creates a new stemming rule with the specified suffix, ending, and avoid set

Parameters:

suffix - the suffix that should be stripped from a word; should not be null, empty, or all whitespace.

ending - the ending that should be stripped from a word; should not be null, but may be empty or all whitespace.

pos - the part of speech to which this rule applies, may not be null

ignore - the set of suffixes that, when present, indicate this rule should not be applied. May be null or empty, but not contain nulls or empties.

Throws:

NullPointerException - if the suffix, ending, or pos are null, or the ignore set contains null

NullPointerException - if the suffix is empty or all whitespace, or the ignore set contains a string which is empty or all whitespace

Since:

JWI 2.3.1

Method Detail

getSuffix

public String getSuffix()

Description copied from interface: IStemmingRule

Returns the suffix for this rule. Will never return null, empty, or all whitespace.

Specified by:

getSuffix in interface IStemmingRule

Returns:

the suffix for this rule.

getEnding

public String getEnding()

Description copied from interface: IStemmingRule

Returns the ending for this rule. Will never return null , empty, or all whitespace.

Specified by:

getEnding in interface IStemmingRule

Returns:

the ending for this rule.

getSuffixIgnoreSet

public Set<String> getSuffixIgnoreSet()

Description copied from interface: IStemmingRule

Returns the set of suffixes that should be ignored when applying this stemming rule. This method will never return null, but it may return an empty set. The ignore set will not include the string returned by IStemmingRule.getSuffix().

Specified by:

getSuffixIgnoreSet in interface IStemmingRule

Returns:

a non-null but possibly empty set of suffixes to be ignored

getPOS

public POS getPOS()

Description copied from interface: IHasPOS

Returns the associated part of speech for this object. If this object is not associated with any particular part of speech, this method may return null.

Specified by:

getPOS in interface IHasPOS

Returns:

The associated part of speech, or null if none.

apply

public String apply(String word)

Description copied from interface: IStemmingRule

Applies this rule to the given word. The word should not be null, but may be empty. If the rule cannot be applied to the word, this method returns null. This call is equivalent to calling IStemmingRule.apply(String, String) with null as the second argument

Specified by:

apply in interface IStemmingRule

Parameters:

word - the word to which the stemming rule should be applied.

Returns:

the root of the word, or null if the rule cannot be applied to this word

apply

public String apply(String word,
                    String suffix)

Description copied from interface: IStemmingRule

Applies this rule to the given word, adding the specified suffix to the end of the returned string. If the rule cannot be applied to the word, this method returns null.

Specified by:

apply in interface IStemmingRule

Parameters:

word - the word to which the stemming rule should be applied.

suffix - a suffix that should be appended to the root once it has been derived; may be null.

Returns:

the root of the word, or null if the rule cannot be applied to this word