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BMPattern.javaAPI DocJava SE 5 API10438Fri Aug 26 14:55:48 BST 2005com.sun.org.apache.xerces.internal.impl.xpath.regex

BMPattern

public class BMPattern extends Object
Boyer-Moore searcher.
version
$Id: BMPattern.java,v 1.3 2002/08/09 15:18:17 neilg Exp $

Fields Summary
char[]
pattern
int[]
shiftTable
boolean
ignoreCase
Constructors Summary
public BMPattern(String pat, boolean ignoreCase)

        this(pat, 256, ignoreCase);
    
public BMPattern(String pat, int tableSize, boolean ignoreCase)

        this.pattern = pat.toCharArray();
        this.shiftTable = new int[tableSize];
        this.ignoreCase = ignoreCase;

        int length = pattern.length;
        for (int i = 0;  i < this.shiftTable.length;  i ++)
            this.shiftTable[i] = length;

        for (int i = 0;  i < length;  i ++) {
            char ch = this.pattern[i];
            int diff = length-i-1;
            int index = ch % this.shiftTable.length;
            if (diff < this.shiftTable[index])
                this.shiftTable[index] = diff;
            if (this.ignoreCase) {
                ch = Character.toUpperCase(ch);
                index = ch % this.shiftTable.length;
                if (diff < this.shiftTable[index])
                    this.shiftTable[index] = diff;
                ch = Character.toLowerCase(ch);
                index = ch % this.shiftTable.length;
                if (diff < this.shiftTable[index])
                    this.shiftTable[index] = diff;
            }
        }
    
Methods Summary
public intmatches(java.text.CharacterIterator iterator, int start, int limit)

return
-1 if iterator does not contain this pattern.

        if (this.ignoreCase)  return this.matchesIgnoreCase(iterator, start, limit);
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                if ((ch = iterator.setIndex(--index)) != this.pattern[--pindex])
                    break;
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    
public intmatches(java.lang.String str, int start, int limit)

return
-1 if str does not contain this pattern.

        if (this.ignoreCase)  return this.matchesIgnoreCase(str, start, limit);
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            //System.err.println("Starts at "+index);
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                if ((ch = str.charAt(--index)) != this.pattern[--pindex])
                    break;
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    
public intmatches(char[] chars, int start, int limit)

return
-1 if chars does not contain this pattern.

        if (this.ignoreCase)  return this.matchesIgnoreCase(chars, start, limit);
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            //System.err.println("Starts at "+index);
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                if ((ch = chars[--index]) != this.pattern[--pindex])
                    break;
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    
intmatchesIgnoreCase(java.text.CharacterIterator iterator, int start, int limit)

        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                char ch1 = ch = iterator.setIndex(--index);
                char ch2 = this.pattern[--pindex];
                if (ch1 != ch2) {
                    ch1 = Character.toUpperCase(ch1);
                    ch2 = Character.toUpperCase(ch2);
                    if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2))
                        break;
                }
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    
intmatchesIgnoreCase(java.lang.String text, int start, int limit)

        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                char ch1 = ch = text.charAt(--index);
                char ch2 = this.pattern[--pindex];
                if (ch1 != ch2) {
                    ch1 = Character.toUpperCase(ch1);
                    ch2 = Character.toUpperCase(ch2);
                    if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2))
                        break;
                }
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    
intmatchesIgnoreCase(char[] chars, int start, int limit)

        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                char ch1 = ch = chars[--index];
                char ch2 = this.pattern[--pindex];
                if (ch1 != ch2) {
                    ch1 = Character.toUpperCase(ch1);
                    ch2 = Character.toUpperCase(ch2);
                    if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2))
                        break;
                }
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;