jpayne@69: // © 2016 and later: Unicode, Inc. and others.
jpayne@69: // License & terms of use: http://www.unicode.org/copyright.html
jpayne@69: /*
jpayne@69: **********************************************************************
jpayne@69: * Copyright (C) 1999-2010, International Business Machines Corporation and others.
jpayne@69: * All Rights Reserved.
jpayne@69: **********************************************************************
jpayne@69: *   Date        Name        Description
jpayne@69: *   11/17/99    aliu        Creation.
jpayne@69: **********************************************************************
jpayne@69: */
jpayne@69: #ifndef UNIFILT_H
jpayne@69: #define UNIFILT_H
jpayne@69: 
jpayne@69: #include "unicode/utypes.h"
jpayne@69: 
jpayne@69: #if U_SHOW_CPLUSPLUS_API
jpayne@69: 
jpayne@69: #include "unicode/unifunct.h"
jpayne@69: #include "unicode/unimatch.h"
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \file 
jpayne@69:  * \brief C++ API: Unicode Filter
jpayne@69:  */
jpayne@69: 
jpayne@69: U_NAMESPACE_BEGIN
jpayne@69: 
jpayne@69: /**
jpayne@69:  * U_ETHER is used to represent character values for positions outside
jpayne@69:  * a range.  For example, transliterator uses this to represent
jpayne@69:  * characters outside the range contextStart..contextLimit-1.  This
jpayne@69:  * allows explicit matching by rules and UnicodeSets of text outside a
jpayne@69:  * defined range.
jpayne@69:  * @stable ICU 3.0
jpayne@69:  */
jpayne@69: #define U_ETHER ((char16_t)0xFFFF)
jpayne@69: 
jpayne@69: /**
jpayne@69:  *
jpayne@69:  * <code>UnicodeFilter</code> defines a protocol for selecting a
jpayne@69:  * subset of the full range (U+0000 to U+10FFFF) of Unicode characters.
jpayne@69:  * Currently, filters are used in conjunction with classes like {@link
jpayne@69:  * Transliterator} to only process selected characters through a
jpayne@69:  * transformation.
jpayne@69:  *
jpayne@69:  * <p>Note: UnicodeFilter currently stubs out two pure virtual methods
jpayne@69:  * of its base class, UnicodeMatcher.  These methods are toPattern()
jpayne@69:  * and matchesIndexValue().  This is done so that filter classes that
jpayne@69:  * are not actually used as matchers -- specifically, those in the
jpayne@69:  * UnicodeFilterLogic component, and those in tests -- can continue to
jpayne@69:  * work without defining these methods.  As long as a filter is not
jpayne@69:  * used in an RBT during real transliteration, these methods will not
jpayne@69:  * be called.  However, this breaks the UnicodeMatcher base class
jpayne@69:  * protocol, and it is not a correct solution.
jpayne@69:  *
jpayne@69:  * <p>In the future we may revisit the UnicodeMatcher / UnicodeFilter
jpayne@69:  * hierarchy and either redesign it, or simply remove the stubs in
jpayne@69:  * UnicodeFilter and force subclasses to implement the full
jpayne@69:  * UnicodeMatcher protocol.
jpayne@69:  *
jpayne@69:  * @see UnicodeFilterLogic
jpayne@69:  * @stable ICU 2.0
jpayne@69:  */
jpayne@69: class U_COMMON_API UnicodeFilter : public UnicodeFunctor, public UnicodeMatcher {
jpayne@69: 
jpayne@69: public:
jpayne@69:     /**
jpayne@69:      * Destructor
jpayne@69:      * @stable ICU 2.0
jpayne@69:      */
jpayne@69:     virtual ~UnicodeFilter();
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * Clones this object polymorphically.
jpayne@69:      * The caller owns the result and should delete it when done.
jpayne@69:      * @return clone, or nullptr if an error occurred
jpayne@69:      * @stable ICU 2.4
jpayne@69:      */
jpayne@69:     virtual UnicodeFilter* clone() const = 0;
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * Returns <tt>true</tt> for characters that are in the selected
jpayne@69:      * subset.  In other words, if a character is <b>to be
jpayne@69:      * filtered</b>, then <tt>contains()</tt> returns
jpayne@69:      * <b><tt>false</tt></b>.
jpayne@69:      * @stable ICU 2.0
jpayne@69:      */
jpayne@69:     virtual UBool contains(UChar32 c) const = 0;
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * UnicodeFunctor API.  Cast 'this' to a UnicodeMatcher* pointer
jpayne@69:      * and return the pointer.
jpayne@69:      * @stable ICU 2.4
jpayne@69:      */
jpayne@69:     virtual UnicodeMatcher* toMatcher() const;
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * Implement UnicodeMatcher API.
jpayne@69:      * @stable ICU 2.4
jpayne@69:      */
jpayne@69:     virtual UMatchDegree matches(const Replaceable& text,
jpayne@69:                                  int32_t& offset,
jpayne@69:                                  int32_t limit,
jpayne@69:                                  UBool incremental);
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * UnicodeFunctor API.  Nothing to do.
jpayne@69:      * @stable ICU 2.4
jpayne@69:      */
jpayne@69:     virtual void setData(const TransliterationRuleData*);
jpayne@69: 
jpayne@69:     /**
jpayne@69:      * ICU "poor man's RTTI", returns a UClassID for this class.
jpayne@69:      *
jpayne@69:      * @stable ICU 2.2
jpayne@69:      */
jpayne@69:     static UClassID U_EXPORT2 getStaticClassID();
jpayne@69: 
jpayne@69: protected:
jpayne@69: 
jpayne@69:     /*
jpayne@69:      * Since this class has pure virtual functions,
jpayne@69:      * a constructor can't be used.
jpayne@69:      * @stable ICU 2.0
jpayne@69:      */
jpayne@69: /*    UnicodeFilter();*/
jpayne@69: };
jpayne@69: 
jpayne@69: /*inline UnicodeFilter::UnicodeFilter() {}*/
jpayne@69: 
jpayne@69: U_NAMESPACE_END
jpayne@69: 
jpayne@69: #endif /* U_SHOW_CPLUSPLUS_API */
jpayne@69: 
jpayne@69: #endif