org.terrier.structures.postings
Class PhraseIterablePosting

java.lang.Object
  org.terrier.structures.postings.IterablePostingImpl
      org.terrier.structures.postings.ANDIterablePosting
          org.terrier.structures.postings.PhraseIterablePosting

All Implemented Interfaces:

Closeable, BlockPosting, IterablePosting, Posting

public class PhraseIterablePosting
extends ANDIterablePosting
implements BlockPosting

Implementation of an IterablePosting for block indices that returns only documents that match a multi-term phase.

Since:

3.5

Author:

Craig Macdonald

Field Summary

Fields inherited from class org.terrier.structures.postings.ANDIterablePosting

currentId, frequency, ips, termCount

Fields inherited from interface org.terrier.structures.postings.IterablePosting

EOL

Constructor Summary

PhraseIterablePosting(IterablePosting[] _ips, Pointer[] _p, boolean recordPositions)

Method Summary

WritablePosting	asWritablePosting() Copies this posting to one free of an iterator.
protected boolean	calculateFrequency() returns true if the document matches
static IterablePosting	createPhrasePostingList(Pointer[] ps, PostingIndex<Pointer> invIndex, boolean savePositions)
static IterablePosting	createPhrasePostingList(String[] terms, Lexicon<String> lex, PostingIndex<Pointer> invIndex, boolean savePositions)
int[]	getPositions() Return positions of occurrences

Methods inherited from class org.terrier.structures.postings.ANDIterablePosting

close, endOfPostings, getDocumentLength, getFrequency, getId, next, setId

Methods inherited from class org.terrier.structures.postings.IterablePostingImpl

next

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.terrier.structures.postings.Posting

getDocumentLength, getFrequency, getId, setId

Constructor Detail

PhraseIterablePosting

public PhraseIterablePosting(IterablePosting[] _ips,
                             Pointer[] _p,
                             boolean recordPositions)
                      throws IOException

Throws:

IOException

Method Detail

asWritablePosting

public WritablePosting asWritablePosting()

Description copied from interface: Posting

Copies this posting to one free of an iterator. Kind of like a clone.

Specified by:

asWritablePosting in interface Posting

Overrides:

asWritablePosting in class ANDIterablePosting

Returns:

an identical posting, but which can be maniulated free of this iterator

calculateFrequency

protected boolean calculateFrequency()

Description copied from class: ANDIterablePosting

returns true if the document matches

Overrides:

calculateFrequency in class ANDIterablePosting

getPositions

public int[] getPositions()

Description copied from interface: BlockPosting

Return positions of occurrences

Specified by:

getPositions in interface BlockPosting

createPhrasePostingList

public static IterablePosting createPhrasePostingList(Pointer[] ps,
                                                      PostingIndex<Pointer> invIndex,
                                                      boolean savePositions)
                                               throws IOException

Throws:

IOException

createPhrasePostingList

public static IterablePosting createPhrasePostingList(String[] terms,
                                                      Lexicon<String> lex,
                                                      PostingIndex<Pointer> invIndex,
                                                      boolean savePositions)
                                               throws IOException

Throws:

IOException