org.languagetool.rules.patterns

Class Unifier

java.lang.Object

org.languagetool.rules.patterns.Unifier

public class Unifier
extends Object

Implements unification of features over tokens.

Author:

Marcin Milkowski

Constructor Summary

Constructors

Constructor and Description
Unifier(Map<org.languagetool.rules.patterns.EquivalenceTypeLocator,PatternToken> equivalenceTypes, Map<String,List<String>> equivalenceFeatures) Instantiates the unifier.

Method Summary

Modifier and Type	Method and Description
void	addNeutralElement(AnalyzedTokenReadings analyzedTokenReadings) Used to add neutral elements (AnalyzedTokenReadings to the unified sequence.
boolean	getFinalUnificationValue(Map<String,List<String>> uFeatures) Make sure that we really matched all the required features of the unification.
AnalyzedTokenReadings[]	getFinalUnified() Used for getting a unified sequence in case when simple test method isUnified(AnalyzedToken, Map, boolean)} was used.
AnalyzedTokenReadings[]	getUnifiedTokens() Gets a full sequence of filtered tokens.
protected boolean	isSatisfied(AnalyzedToken aToken, Map<String,List<String>> uFeatures) Tests if a token has shared features with other tokens.
boolean	isUnified(AnalyzedToken matchToken, Map<String,List<String>> uFeatures, boolean lastReading)
boolean	isUnified(AnalyzedToken matchToken, Map<String,List<String>> uFeatures, boolean lastReading, boolean isMatched) Tests if the token sequence is unified.
void	reset() Resets after use of unification.
void	startNextToken() Call after every complete token (AnalyzedTokenReadings) checked.
void	startUnify() Starts testing only those equivalences that were previously matched.

Methods inherited from class java.lang.Object

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

Constructor Detail

Unifier

public Unifier(Map<org.languagetool.rules.patterns.EquivalenceTypeLocator,PatternToken> equivalenceTypes,
               Map<String,List<String>> equivalenceFeatures)

Instantiates the unifier.

Method Detail

isSatisfied

protected final boolean isSatisfied(AnalyzedToken aToken,
                                    Map<String,List<String>> uFeatures)

Tests if a token has shared features with other tokens.

Parameters:

aToken - token to be tested

uFeatures - features to be tested

Returns:

true if the token shares this type of feature with other tokens

startNextToken

public final void startNextToken()

Call after every complete token (AnalyzedTokenReadings) checked.

startUnify

public final void startUnify()

Starts testing only those equivalences that were previously matched.

getFinalUnificationValue

public final boolean getFinalUnificationValue(Map<String,List<String>> uFeatures)

Make sure that we really matched all the required features of the unification.

Parameters:

uFeatures - Features to be checked

Returns:

True if the token sequence has been found.

Since:

2.5

reset

public final void reset()

Resets after use of unification. Required.

getUnifiedTokens

@Nullable
public final AnalyzedTokenReadings[] getUnifiedTokens()

Gets a full sequence of filtered tokens.

Returns:

Array of AnalyzedTokenReadings that match equivalence relation defined for features tested, or null

isUnified

public final boolean isUnified(AnalyzedToken matchToken,
                               Map<String,List<String>> uFeatures,
                               boolean lastReading,
                               boolean isMatched)

Tests if the token sequence is unified.

Usage note: to test if the sequence of tokens is unified (i.e., shares a group of features, such as the same gender, number, grammatical case etc.), you need to test all tokens but the last one in the following way: call isUnified() for every reading of a token, and set lastReading to true. For the last token, check the truth value returned by this method. In previous cases, it may actually be discarded before the final check. See AbstractPatternRule for an example.

To make it work in XML rules, the Elements built based on <token>s inside the unify block have to be processed in a special way: namely the last Element has to be marked as the last one (by using PatternToken.setLastInUnification()).

Parameters:

matchToken - AnalyzedToken token to unify

lastReading - true when the matchToken is the last reading in the AnalyzedTokenReadings

isMatched - true if the reading matches the element in the pattern rule, otherwise the reading is not considered in the unification

Returns:

true if the tokens in the sequence are unified

isUnified

public final boolean isUnified(AnalyzedToken matchToken,
                               Map<String,List<String>> uFeatures,
                               boolean lastReading)

addNeutralElement

public final void addNeutralElement(AnalyzedTokenReadings analyzedTokenReadings)

Used to add neutral elements (AnalyzedTokenReadings to the unified sequence. Useful if the sequence contains punctuation or connectives, for example.

Parameters:

analyzedTokenReadings - A neutral element to be added.

Since:

2.5

getFinalUnified

@Nullable
public final AnalyzedTokenReadings[] getFinalUnified()

Used for getting a unified sequence in case when simple test method isUnified(AnalyzedToken, Map, boolean)} was used.

Returns:

An array of AnalyzedTokenReadings or null when not in unification