/*
* Copyright (C) 2001, 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 RuleBasedTransliterator 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 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 rightmost
* match.
*/
int32_t matchStart;
/**
* Limit offset, in the match text, of the rightmost
* match.
*/
int32_t matchLimit;
};
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_TRANSLITERATION */
#endif