| /* |
| * 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" |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * <code>UnicodeFilter</code> defines a protocol for selecting a |
| * subset of the full range (U+0000 to U+10FFFF) 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 |
| * @stable |
| */ |
| class U_I18N_API UnicodeFilter : public UnicodeMatcher { |
| |
| public: |
| /** |
| * Destructor |
| * @stable |
| */ |
| 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>. |
| * @stable |
| */ |
| 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); |
| |
| protected: |
| |
| UnicodeFilter(); |
| }; |
| |
| inline UnicodeFilter::UnicodeFilter() {} |
| inline UnicodeFilter::~UnicodeFilter() {} |
| |
| U_NAMESPACE_END |
| |
| #endif |