Check in the pristine copy of ICU 4.6...

icu46/source/common/unicode/unimatch.h

+/*
+* 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
+ */
+
+
+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