org.jscience.linguistics.search
Class BoyerMooreHorspoolRaita

java.lang.Object
  org.jscience.linguistics.search.StringSearch
      org.jscience.linguistics.search.BoyerMooreHorspool
          org.jscience.linguistics.search.BoyerMooreHorspoolRaita

public class BoyerMooreHorspoolRaita
extends BoyerMooreHorspool

An implementation of Raita's enhancement to the Boyer-Moore-Horspool String searching algorithm. See "Tuning the Boyer-Moore-Horspool string searching algorithm" (appeared in Software - Practice & Experience, 22(10):879-884).

This algorithm is slightly faster than the BoyerMooreHorspool algorithm for the searchChars and searchString methods. It's searchBytes methods are slightly slower.

 Preprocessing: O(m + ∑) time
 

 Processing   : O(mn) worst case
 

See Also:

http://www.cs.ubc.ca/local/reading/proceedings/spe91-95/spe/vol22/issue10/spe787tr.pdf

Nested Class Summary

Nested classes/interfaces inherited from class org.jscience.linguistics.search.StringSearch

StringSearch.Dispatch, StringSearch.ReflectionDispatch

Field Summary

Fields inherited from class org.jscience.linguistics.search.StringSearch

activeDispatch, useNative

Constructor Summary

BoyerMooreHorspoolRaita()
Constructor for BoyerMooreHorspoolRaita.

Method Summary

int	searchBytes(byte[] text, int textStart, int textEnd, byte[] pattern, java.lang.Object processed) Returns the position in the text at which the pattern was found.
int	searchChars(char[] text, int textStart, int textEnd, char[] pattern, java.lang.Object processed) Returns the index of the pattern in the text using the pre-processed Object.

Methods inherited from class org.jscience.linguistics.search.BoyerMooreHorspool

processBytes, processChars

Methods inherited from class org.jscience.linguistics.search.StringSearch

createCharIntMap, createCharIntMap, equals, hashCode, index, processString, searchBytes, searchBytes, searchBytes, searchBytes, searchBytes, searchChars, searchChars, searchChars, searchChars, searchChars, searchString, searchString, searchString, searchString, searchString, searchString, toString, toStringBuffer, usesNative, usesReflection

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BoyerMooreHorspoolRaita

public BoyerMooreHorspoolRaita()

Constructor for BoyerMooreHorspoolRaita. Note that it is not required to create multiple instances.

Method Detail

searchBytes

public int searchBytes(byte[] text,
                       int textStart,
                       int textEnd,
                       byte[] pattern,
                       java.lang.Object processed)

Description copied from class: StringSearch

Returns the position in the text at which the pattern was found. Returns -1 if the pattern was not found.

Overrides:

searchBytes in class BoyerMooreHorspool

Parameters:

text - text the byte array containing the text, may not be null

textStart - at which position in the text the comparing should start

textEnd - at which position in the text comparing should stop

pattern - the pattern to search for, may not be null

processed - an Object as returned from StringSearch.processBytes(byte[]), may not be null

Returns:

the position in the text or -1 if the pattern was not found

See Also:

StringSearch.searchBytes(byte[], int,int,byte[],java.lang.Object)

searchChars

public int searchChars(char[] text,
                       int textStart,
                       int textEnd,
                       char[] pattern,
                       java.lang.Object processed)

Description copied from class: StringSearch

Returns the index of the pattern in the text using the pre-processed Object. Returns -1 if the pattern was not found.

Overrides:

searchChars in class BoyerMooreHorspool

Parameters:

text - the String containing the text, may not be null

textStart - at which position in the text the comparing should start

textEnd - at which position in the text comparing should stop

pattern - the pattern to search for, may not be null

processed - an Object as returned from StringSearch.processChars(char[]) or StringSearch.processString(String), may not be null

Returns:

the position in the text or -1 if the pattern was not found

See Also:

StringSearch.searchChars(char[], int,int,char[],Object)