// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* * Copyright (C) 2001-2005, International Business Machines Corporation and others. All Rights Reserved. ********************************************************************** * Date Name Description * 07/18/01 aliu Creation. ********************************************************************** */ #ifndef UNIMATCH_H #define UNIMATCH_H #include "unicode/utypes.h" /** * \file * \brief C++ API: Unicode Matcher */ #if U_SHOW_CPLUSPLUS_API U_NAMESPACE_BEGIN class Replaceable; class UnicodeString; class UnicodeSet; /** * Constants returned by <code>UnicodeMatcher::matches()</code> * indicating the degree of match. * @stable ICU 2.4 */ enum UMatchDegree { /** * Constant returned by <code>matches()</code> indicating a * mismatch between the text and this matcher. The text contains * a character which does not match, or the text does not contain * all desired characters for a non-incremental match. * @stable ICU 2.4 */ U_MISMATCH, /** * Constant returned by <code>matches()</code> indicating a * partial match between the text and this matcher. This value is * only returned for incremental match operations. All characters * of the text match, but more characters are required for a * complete match. Alternatively, for variable-length matchers, * all characters of the text match, and if more characters were * supplied at limit, they might also match. * @stable ICU 2.4 */ U_PARTIAL_MATCH, /** * Constant returned by <code>matches()</code> indicating a * complete match between the text and this matcher. For an * incremental variable-length match, this value is returned if * the given text matches, and it is known that additional * characters would not alter the extent of the match. * @stable ICU 2.4 */ U_MATCH }; /** * <code>UnicodeMatcher</code> defines a protocol for objects that can * match a range of characters in a Replaceable string. * @stable ICU 2.4 */ class U_COMMON_API UnicodeMatcher /* not : public UObject because this is an interface/mixin class */ { public: /** * Destructor. * @stable ICU 2.4 */ virtual ~UnicodeMatcher(); /** * Return a UMatchDegree value indicating the degree of match for * the given text at the given offset. Zero, one, or more * characters may be matched. * * Matching in the forward direction is indicated by limit > * offset. Characters from offset forwards to limit-1 will be * considered for matching. * * Matching in the reverse direction is indicated by limit < * offset. Characters from offset backwards to limit+1 will be * considered for matching. * * If limit == offset then the only match possible is a zero * character match (which subclasses may implement if desired). * * As a side effect, advance the offset parameter to the limit of * the matched substring. In the forward direction, this will be * the index of the last matched character plus one. In the * reverse direction, this will be the index of the last matched * character minus one. * * <p>Note: This method is not const because some classes may * modify their state as the result of a match. * * @param text the text to be matched * @param offset on input, the index into text at which to begin * matching. On output, the limit of the matched text. The * number of matched characters is the output value of offset * minus the input value. Offset should always point to the * HIGH SURROGATE (leading code unit) of a pair of surrogates, * both on entry and upon return. * @param limit the limit index of text to be matched. Greater * than offset for a forward direction match, less than offset for * a backward direction match. The last character to be * considered for matching will be text.charAt(limit-1) in the * forward direction or text.charAt(limit+1) in the backward * direction. * @param incremental if TRUE, then assume further characters may * be inserted at limit and check for partial matching. Otherwise * assume the text as given is complete. * @return a match degree value indicating a full match, a partial * match, or a mismatch. If incremental is FALSE then * U_PARTIAL_MATCH should never be returned. * @stable ICU 2.4 */ virtual UMatchDegree matches(const Replaceable& text, int32_t& offset, int32_t limit, UBool incremental) = 0; /** * Returns a string representation of this matcher. If the result of * calling this function is passed to the appropriate parser, it * will produce another matcher that is equal to this one. * @param result the string to receive the pattern. Previous * contents will be deleted. * @param escapeUnprintable if TRUE then convert unprintable * character to their hex escape representations, \\uxxxx or * \\Uxxxxxxxx. Unprintable characters are those other than * U+000A, U+0020..U+007E. * @stable ICU 2.4 */ virtual UnicodeString& toPattern(UnicodeString& result, UBool escapeUnprintable = FALSE) const = 0; /** * Returns TRUE if this matcher will match a character c, where c * & 0xFF == v, at offset, in the forward direction (with limit > * offset). This is used by <tt>RuleBasedTransliterator</tt> for * indexing. * @stable ICU 2.4 */ virtual UBool matchesIndexValue(uint8_t v) const = 0; /** * 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 * @stable ICU 2.4 */ virtual void addMatchSetTo(UnicodeSet& toUnionTo) const = 0; }; U_NAMESPACE_END #endif /* U_SHOW_CPLUSPLUS_API */ #endif