com.ibm.icu.text.Quantifier Maven / Gradle / Ivy
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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
* Copyright (C) 2001-2011, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.text;
import com.ibm.icu.impl.Utility;
class Quantifier implements UnicodeMatcher {
private UnicodeMatcher matcher;
private int minCount;
private int maxCount;
/**
* Maximum count a quantifier can have.
*/
public static final int MAX = Integer.MAX_VALUE;
public Quantifier(UnicodeMatcher theMatcher,
int theMinCount, int theMaxCount) {
if (theMatcher == null || theMinCount < 0 || theMaxCount < 0 || theMinCount > theMaxCount) {
throw new IllegalArgumentException();
}
matcher = theMatcher;
minCount = theMinCount;
maxCount = theMaxCount;
}
/**
* Implement UnicodeMatcher API.
*/
public int matches(Replaceable text,
int[] offset,
int limit,
boolean incremental) {
int start = offset[0];
int count = 0;
while (count < maxCount) {
int pos = offset[0];
int m = matcher.matches(text, offset, limit, incremental);
if (m == U_MATCH) {
++count;
if (pos == offset[0]) {
// If offset has not moved we have a zero-width match.
// Don't keep matching it infinitely.
break;
}
} else if (incremental && m == U_PARTIAL_MATCH) {
return U_PARTIAL_MATCH;
} else {
break;
}
}
if (incremental && offset[0] == limit) {
return U_PARTIAL_MATCH;
}
if (count >= minCount) {
return U_MATCH;
}
offset[0] = start;
return U_MISMATCH;
}
/**
* Implement UnicodeMatcher API
*/
public String toPattern(boolean escapeUnprintable) {
StringBuilder result = new StringBuilder();
result.append(matcher.toPattern(escapeUnprintable));
if (minCount == 0) {
if (maxCount == 1) {
return result.append('?').toString();
} else if (maxCount == MAX) {
return result.append('*').toString();
}
// else fall through
} else if (minCount == 1 && maxCount == MAX) {
return result.append('+').toString();
}
result.append('{');
result.append(Utility.hex(minCount,1));
result.append(',');
if (maxCount != MAX) {
result.append(Utility.hex(maxCount,1));
}
result.append('}');
return result.toString();
}
/**
* Implement UnicodeMatcher API
*/
public boolean matchesIndexValue(int v) {
return (minCount == 0) || matcher.matchesIndexValue(v);
}
/**
* Implementation of UnicodeMatcher API. Union the set of all
* characters that may be matched by this object into the given
* set.
* @param toUnionTo the set into which to union the source characters
* @returns a reference to toUnionTo
*/
public void addMatchSetTo(UnicodeSet toUnionTo) {
if (maxCount > 0) {
matcher.addMatchSetTo(toUnionTo);
}
}
}
//eof