| | 1 | /* |
| | 2 | ********************************************************************** |
| | 3 | * Copyright (C) 1999-2006, International Business Machines Corporation and others. |
| | 4 | * All Rights Reserved. |
| | 5 | ********************************************************************** |
| | 6 | * Date Name Description |
| | 7 | * 11/17/99 aliu Creation. |
| | 8 | ********************************************************************** |
| | 9 | */ |
| | 10 | #ifndef UNIFILT_H |
| | 11 | #define UNIFILT_H |
| | 12 | |
| | 13 | #include "unicode/unifunct.h" |
| | 14 | #include "unicode/unimatch.h" |
| | 15 | |
| | 16 | /** |
| | 17 | * \file |
| | 18 | * \brief C++ API: Unicode Filter |
| | 19 | */ |
| | 20 | |
| | 21 | U_NAMESPACE_BEGIN |
| | 22 | |
| | 23 | /** |
| | 24 | * U_ETHER is used to represent character values for positions outside |
| | 25 | * a range. For example, transliterator uses this to represent |
| | 26 | * characters outside the range contextStart..contextLimit-1. This |
| | 27 | * allows explicit matching by rules and UnicodeSets of text outside a |
| | 28 | * defined range. |
| | 29 | * @stable ICU 3.0 |
| | 30 | */ |
| | 31 | #define U_ETHER ((UChar)0xFFFF) |
| | 32 | |
| | 33 | /** |
| | 34 | * |
| | 35 | * <code>UnicodeFilter</code> defines a protocol for selecting a |
| | 36 | * subset of the full range (U+0000 to U+10FFFF) of Unicode characters. |
| | 37 | * Currently, filters are used in conjunction with classes like {@link |
| | 38 | * Transliterator} to only process selected characters through a |
| | 39 | * transformation. |
| | 40 | * |
| | 41 | * <p>Note: UnicodeFilter currently stubs out two pure virtual methods |
| | 42 | * of its base class, UnicodeMatcher. These methods are toPattern() |
| | 43 | * and matchesIndexValue(). This is done so that filter classes that |
| | 44 | * are not actually used as matchers -- specifically, those in the |
| | 45 | * UnicodeFilterLogic component, and those in tests -- can continue to |
| | 46 | * work without defining these methods. As long as a filter is not |
| | 47 | * used in an RBT during real transliteration, these methods will not |
| | 48 | * be called. However, this breaks the UnicodeMatcher base class |
| | 49 | * protocol, and it is not a correct solution. |
| | 50 | * |
| | 51 | * <p>In the future we may revisit the UnicodeMatcher / UnicodeFilter |
| | 52 | * hierarchy and either redesign it, or simply remove the stubs in |
| | 53 | * UnicodeFilter and force subclasses to implement the full |
| | 54 | * UnicodeMatcher protocol. |
| | 55 | * |
| | 56 | * @see UnicodeFilterLogic |
| | 57 | * @stable ICU 2.0 |
| | 58 | */ |
| | 59 | class U_COMMON_API UnicodeFilter : public UnicodeFunctor, public UnicodeMatcher { |
| | 60 | |
| | 61 | public: |
| | 62 | /** |
| | 63 | * Destructor |
| | 64 | * @stable ICU 2.0 |
| | 65 | */ |
| | 66 | virtual ~UnicodeFilter(); |
| | 67 | |
| | 68 | /** |
| | 69 | * Returns <tt>true</tt> for characters that are in the selected |
| | 70 | * subset. In other words, if a character is <b>to be |
| | 71 | * filtered</b>, then <tt>contains()</tt> returns |
| | 72 | * <b><tt>false</tt></b>. |
| | 73 | * @stable ICU 2.0 |
| | 74 | */ |
| | 75 | virtual UBool contains(UChar32 c) const = 0; |
| | 76 | |
| | 77 | /** |
| | 78 | * UnicodeFunctor API. Cast 'this' to a UnicodeMatcher* pointer |
| | 79 | * and return the pointer. |
| | 80 | * @stable ICU 2.4 |
| | 81 | */ |
| | 82 | virtual UnicodeMatcher* toMatcher() const; |
| | 83 | |
| | 84 | /** |
| | 85 | * Implement UnicodeMatcher API. |
| | 86 | * @stable ICU 2.4 |
| | 87 | */ |
| | 88 | virtual UMatchDegree matches(const Replaceable& text, |
| | 89 | int32_t& offset, |
| | 90 | int32_t limit, |
| | 91 | UBool incremental); |
| | 92 | |
| | 93 | /** |
| | 94 | * UnicodeFunctor API. Nothing to do. |
| | 95 | * @stable ICU 2.4 |
| | 96 | */ |
| | 97 | virtual void setData(const TransliterationRuleData*); |
| | 98 | |
| | 99 | /** |
| | 100 | * ICU "poor man's RTTI", returns a UClassID for the actual class. |
| | 101 | * |
| | 102 | * @stable ICU 2.2 |
| | 103 | */ |
| | 104 | virtual UClassID getDynamicClassID() const = 0; |
| | 105 | |
| | 106 | /** |
| | 107 | * ICU "poor man's RTTI", returns a UClassID for this class. |
| | 108 | * |
| | 109 | * @stable ICU 2.2 |
| | 110 | */ |
| | 111 | static UClassID U_EXPORT2 getStaticClassID(); |
| | 112 | |
| | 113 | protected: |
| | 114 | |
| | 115 | /* |
| | 116 | * Since this class has pure virtual functions, |
| | 117 | * a constructor can't be used. |
| | 118 | * @stable ICU 2.0 |
| | 119 | */ |
| | 120 | /* UnicodeFilter();*/ |
| | 121 | }; |
| | 122 | |
| | 123 | /*inline UnicodeFilter::UnicodeFilter() {}*/ |
| | 124 | |
| | 125 | U_NAMESPACE_END |
| | 126 | |
| | 127 | #endif |
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