Check in the pristine copy of ICU 4.6...

icu46/source/i18n/strmatch.h

+/*
+ * Copyright (C) 2001-2004, International Business Machines Corporation
+ * and others. All Rights Reserved.
+ **********************************************************************
+ *   Date        Name        Description
+ *   07/23/01    aliu        Creation.
+ **********************************************************************
+ */
+#ifndef STRMATCH_H
+#define STRMATCH_H
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_TRANSLITERATION
+
+#include "unicode/unistr.h"
+#include "unicode/unifunct.h"
+#include "unicode/unimatch.h"
+#include "unicode/unirepl.h"
+
+U_NAMESPACE_BEGIN
+
+class TransliterationRuleData;
+
+/**
+ * An object that matches a fixed input string, implementing the
+ * UnicodeMatcher API.  This object also implements the
+ * UnicodeReplacer API, allowing it to emit the matched text as
+ * output.  Since the match text may contain flexible match elements,
+ * such as UnicodeSets, the emitted text is not the match pattern, but
+ * instead a substring of the actual matched text.  Following
+ * convention, the output text is the leftmost match seen up to this
+ * point.
+ *
+ * A StringMatcher may represent a segment, in which case it has a
+ * positive segment number.  This affects how the matcher converts
+ * itself to a pattern but does not otherwise affect its function.
+ *
+ * A StringMatcher that is not a segment should not be used as a
+ * UnicodeReplacer.
+ */
+class StringMatcher : public UnicodeFunctor, public UnicodeMatcher, public UnicodeReplacer {
+
+ public:
+
+    /**
+     * Construct a matcher that matches the given pattern string.
+     * @param string the pattern to be matched, possibly containing
+     * stand-ins that represent nested UnicodeMatcher objects.
+     * @param start inclusive start index of text to be replaced
+     * @param limit exclusive end index of text to be replaced;
+     * must be greater than or equal to start
+     * @param segmentNum the segment number from 1..n, or 0 if this is
+     * not a segment.
+     * @param data context object mapping stand-ins to
+     * UnicodeMatcher objects.
+     */
+    StringMatcher(const UnicodeString& string,
+                  int32_t start,
+                  int32_t limit,
+                  int32_t segmentNum,
+                  const TransliterationRuleData& data);
+
+    /**
+     * Copy constructor
+     * @param o  the object to be copied.
+     */
+    StringMatcher(const StringMatcher& o);
+        
+    /**
+     * Destructor
+     */
+    virtual ~StringMatcher();
+
+    /**
+     * Implement UnicodeFunctor
+     * @return a copy of the object.
+     */
+    virtual UnicodeFunctor* clone() const;
+
+    /**
+     * UnicodeFunctor API.  Cast 'this' to a UnicodeMatcher* pointer
+     * and return the pointer.
+     * @return the UnicodeMatcher point.
+     */
+    virtual UnicodeMatcher* toMatcher() const;
+
+    /**
+     * UnicodeFunctor API.  Cast 'this' to a UnicodeReplacer* pointer
+     * and return the pointer.
+     * @return the UnicodeReplacer pointer.
+     */
+    virtual UnicodeReplacer* toReplacer() const;
+
+    /**
+     * Implement UnicodeMatcher
+     * @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.
+     */
+    virtual UMatchDegree matches(const Replaceable& text,
+                                 int32_t& offset,
+                                 int32_t limit,
+                                 UBool incremental);
+
+    /**
+     * Implement UnicodeMatcher
+     * @param result            Output param to receive the pattern.
+     * @param escapeUnprintable if True then escape the unprintable characters.
+     * @return                  A reference to 'result'.
+     */
+    virtual UnicodeString& toPattern(UnicodeString& result,
+                                     UBool escapeUnprintable = FALSE) const;
+
+    /**
+     * Implement UnicodeMatcher
+     * 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.
+     * @param v    the given value
+     * @return     TRUE if this matcher will match a character c, 
+     *             where c & 0xFF == v
+     */
+    virtual UBool matchesIndexValue(uint8_t v) const;
+
+    /**
+     * Implement UnicodeMatcher
+     */
+    virtual void addMatchSetTo(UnicodeSet& toUnionTo) const;
+
+    /**
+     * Implement UnicodeFunctor
+     */
+    virtual void setData(const TransliterationRuleData*);
+
+    /**
+     * Replace characters in 'text' from 'start' to 'limit' with the
+     * output text of this object.  Update the 'cursor' parameter to
+     * give the cursor position and return the length of the
+     * replacement text.
+     *
+     * @param text the text to be matched
+     * @param start inclusive start index of text to be replaced
+     * @param limit exclusive end index of text to be replaced;
+     * must be greater than or equal to start
+     * @param cursor output parameter for the cursor position.
+     * Not all replacer objects will update this, but in a complete
+     * tree of replacer objects, representing the entire output side
+     * of a transliteration rule, at least one must update it.
+     * @return the number of 16-bit code units in the text replacing
+     * the characters at offsets start..(limit-1) in text
+     */
+    virtual int32_t replace(Replaceable& text,
+                            int32_t start,
+                            int32_t limit,
+                            int32_t& cursor);
+
+    /**
+     * Returns a string representation of this replacer.  If the
+     * result of calling this function is passed to the appropriate
+     * parser, typically TransliteratorParser, it will produce another
+     * replacer 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 defined by
+     * Utility.isUnprintable().
+     * @return a reference to 'result'.
+     */
+    virtual UnicodeString& toReplacerPattern(UnicodeString& result,
+                                             UBool escapeUnprintable) const;
+
+    /**
+     * Remove any match data.  This must be called before performing a
+     * set of matches with this segment.
+     */
+    void resetMatch();
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     *
+     * @draft ICU 2.2
+     */
+    virtual UClassID getDynamicClassID() const;
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for this class.
+     *
+     * @draft ICU 2.2
+     */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+    /**
+     * Union the set of all characters that may output by this object
+     * into the given set.
+     * @param toUnionTo the set into which to union the output characters
+     */
+    virtual void addReplacementSetTo(UnicodeSet& toUnionTo) const;
+
+ private:
+
+    /**
+     * The text to be matched.
+     */
+    UnicodeString pattern;
+
+    /**
+     * Context object that maps stand-ins to matcher and replacer
+     * objects.
+     */
+    const TransliterationRuleData* data;
+
+    /**
+     * The segment number, 1-based, or 0 if not a segment.
+     */
+    int32_t segmentNumber;
+
+    /**
+     * Start offset, in the match text, of the <em>rightmost</em>
+     * match.
+     */
+    int32_t matchStart;
+
+    /**
+     * Limit offset, in the match text, of the <em>rightmost</em>
+     * match.
+     */
+    int32_t matchLimit;
+
+};
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_TRANSLITERATION */
+
+#endif