Package opennlp.tools.parser

Class ChunkContextGenerator

java.lang.Object

opennlp.tools.parser.ChunkContextGenerator

All Implemented Interfaces:

ChunkerContextGenerator, BeamSearchContextGenerator<TokenTag>

public class ChunkContextGenerator
extends Object
implements ChunkerContextGenerator

Creates predictive context for the pre-chunking phases of parsing.

Constructor Summary

Constructors

Constructor	Description
ChunkContextGenerator()	Initializes a ChunkContextGenerator instance.
ChunkContextGenerator(int cacheSize)	Initializes a ChunkContextGenerator instance with a custom cacheSize.

Method Summary

Modifier and Type	Method	Description
String[]	getContext(int i, String[] words, String[] tags, String[] preds)	Retrieves the contexts for chunking of the specified idx.
String[]	getContext(int index, TokenTag[] sequence, String[] priorDecisions, Object[] additionalContext)	Returns the context for the specified position in the specified sequence (list).

Methods inherited from class java.lang.Object

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

Constructor Details

ChunkContextGenerator

public ChunkContextGenerator()

Initializes a ChunkContextGenerator instance.

ChunkContextGenerator

public ChunkContextGenerator(int cacheSize)

Initializes a ChunkContextGenerator instance with a custom cacheSize.

Parameters:

cacheSize - The cache size. Must be greater than 0 to have an effect.

Method Details

getContext

public String[] getContext(int i,
 String[] words,
 String[] tags,
 String[] preds)

Description copied from interface: ChunkerContextGenerator

Retrieves the contexts for chunking of the specified idx.

Specified by:

getContext in interface ChunkerContextGenerator

Parameters:

i - The index of the token in the specified toks array for which the context should be constructed.

words - The tokens of the sentence. The toString methods of these objects should return the token text.

tags - The POS tags for the specified tokens.

preds - The previous decisions made in the tagging of this sequence. Only indices less than idx will be examined.

Returns:

An array of predictive contexts on which a model basis its decisions.

getContext

public String[] getContext(int index,
 TokenTag[] sequence,
 String[] priorDecisions,
 Object[] additionalContext)

Description copied from interface: BeamSearchContextGenerator

Returns the context for the specified position in the specified sequence (list).

Specified by:

getContext in interface BeamSearchContextGenerator<TokenTag>

Parameters:

index - The index of the sequence.

sequence - The sequence of items over which the beam search is performed.

priorDecisions - The sequence of decisions made prior to the context for which this decision is being made.

additionalContext - Any additional context specific to a class implementing this interface.

Returns:

The context for the specified index in the specified sequence.