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* Copyright (C) 1999, International Business Machines Corporation and others. All Rights Reserved.
* Date Name Description
* 11/17/99 aliu Creation.
#ifndef UNIFILT_H
#define UNIFILT_H
#include "unicode/unimatch.h"
* <code>UnicodeFilter</code> defines a protocol for selecting a
* subset of the full range (U+0000 to U+FFFF) of Unicode characters.
* Currently, filters are used in conjunction with classes like {@link
* Transliterator} to only process selected characters through a
* transformation.
* <p>Note: UnicodeFilter currently stubs out two pure virtual methods
* of its base class, UnicodeMatcher. These methods are toPattern()
* and matchesIndexValue(). This is done so that filter classes that
* are not actually used as matchers -- specifically, those in the
* UnicodeFilterLogic component, and those in tests -- can continue to
* work without defining these methods. As long as a filter is not
* used in an RBT during real transliteration, these methods will not
* be called. However, this breaks the UnicodeMatcher base class
* protocol, and it is not a correct solution.
* <p>In the future we may revisit the UnicodeMatcher / UnicodeFilter
* hierarchy and either redesign it, or simply remove the stubs in
* UnicodeFilter and force subclasses to implement the full
* UnicodeMatcher protocol.
* @see UnicodeFilterLogic
* @draft
class U_I18N_API UnicodeFilter : public UnicodeMatcher {
* Destructor
* @draft */
virtual ~UnicodeFilter();
* Returns <tt>true</tt> for characters that are in the selected
* subset. In other words, if a character is <b>to be
* filtered</b>, then <tt>contains()</tt> returns
* <b><tt>false</tt></b>.
* @draft
virtual UBool contains(UChar32 c) const = 0;
* UnicodeMatcher API. This class stubs this out.
UnicodeString& toPattern(UnicodeString& result,
UBool escapeUnprintable) const;
* UnicodeMatcher API. This class stubs this out.
UBool matchesIndexValue(uint8_t v) const;
* Implement UnicodeMatcher API.
virtual UMatchDegree matches(const Replaceable& text,
int32_t& offset,
int32_t limit,
UBool incremental) const;
inline UnicodeFilter::UnicodeFilter() {}
inline UnicodeFilter::~UnicodeFilter() {}