225 lines
7.2 KiB
C++
225 lines
7.2 KiB
C++
/*
|
|
******************************************************************************
|
|
* Copyright (C) 1996-2009, International Business Machines *
|
|
* Corporation and others. All Rights Reserved. *
|
|
******************************************************************************
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* \brief C++ API: Boyer-Moore StringSearch technology preview
|
|
* \internal ICU 4.0.1 technology preview
|
|
*/
|
|
|
|
#ifndef B_M_SEARCH_H
|
|
#define B_M_SEARCH_H
|
|
|
|
#include "unicode/utypes.h"
|
|
|
|
#if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION
|
|
|
|
#include "unicode/uobject.h"
|
|
#include "unicode/ucol.h"
|
|
|
|
#include "unicode/colldata.h"
|
|
|
|
U_NAMESPACE_BEGIN
|
|
|
|
class BadCharacterTable;
|
|
class GoodSuffixTable;
|
|
class Target;
|
|
|
|
/**
|
|
* BoyerMooreSearch
|
|
*
|
|
* This object holds the information needed to do a Collation sensitive Boyer-Moore search. It encapulates
|
|
* the pattern, the "bad character" and "good suffix" tables, the Collator-based data needed to compute them,
|
|
* and a reference to the text being searched.
|
|
*
|
|
* To do a search, you fist need to get a <code>CollData</code> object by calling <code>CollData::open</code>.
|
|
* Then you construct a <code>BoyerMooreSearch</code> object from the <code>CollData</code> object, the pattern
|
|
* string and the target string. Then you call the <code>search</code> method. Here's a code sample:
|
|
*
|
|
* <pre>
|
|
* void boyerMooreExample(UCollator *collator, UnicodeString *pattern, UnicodeString *target)
|
|
* {
|
|
* UErrorCode status = U_ZERO_ERROR;
|
|
* CollData *collData = CollData::open(collator, status);
|
|
*
|
|
* if (U_FAILURE(status)) {
|
|
* // could not create a CollData object
|
|
* return;
|
|
* }
|
|
*
|
|
* BoyerMooreSearch *search = new BoyerMooreSearch(collData, *patternString, target, status);
|
|
*
|
|
* if (U_FAILURE(status)) {
|
|
* // could not create a BoyerMooreSearch object
|
|
* CollData::close(collData);
|
|
* return;
|
|
* }
|
|
*
|
|
* int32_t offset = 0, start = -1, end = -1;
|
|
*
|
|
* // Find all matches
|
|
* while (search->search(offset, start, end)) {
|
|
* // process the match between start and end
|
|
* ...
|
|
* // advance past the match
|
|
* offset = end;
|
|
* }
|
|
*
|
|
* // at this point, if offset == 0, there were no matches
|
|
* if (offset == 0) {
|
|
* // handle the case of no matches
|
|
* }
|
|
*
|
|
* delete search;
|
|
* CollData::close(collData);
|
|
*
|
|
* // CollData objects are cached, so the call to
|
|
* // CollData::close doesn't delete the object.
|
|
* // Call this if you don't need the object any more.
|
|
* CollData::flushCollDataCache();
|
|
* }
|
|
* </pre>
|
|
*
|
|
* NOTE: This is a technology preview. The final version of this API may not bear any resenblence to this API.
|
|
*
|
|
* Knows linitations:
|
|
* 1) Backwards searching has not been implemented.
|
|
*
|
|
* 2) For Han and Hangul characters, this code ignores any Collation tailorings. In general,
|
|
* this isn't a problem, but in Korean locals, at strength 1, Hangul characters are tailored
|
|
* to be equal to Han characters with the same pronounciation. Because this code ignroes
|
|
* tailorings, searching for a Hangul character will not find a Han character and visa-versa.
|
|
*
|
|
* 3) In some cases, searching for a pattern that needs to be normalized and ends
|
|
* in a discontiguous contraction may fail. The only known cases of this are with
|
|
* the Tibetan script. For example searching for the pattern
|
|
* "\u0F7F\u0F80\u0F81\u0F82\u0F83\u0F84\u0F85" will fail. (This case is artificial. We've
|
|
* been unable to find a pratical, real-world example of this failure.)
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*
|
|
* @see CollData
|
|
*/
|
|
class U_I18N_API BoyerMooreSearch : public UObject
|
|
{
|
|
public:
|
|
/**
|
|
* Construct a <code>BoyerMooreSearch</code> object.
|
|
*
|
|
* @param theData - A <code>CollData</code> object holding the Collator-sensitive data
|
|
* @param patternString - the string for which to search
|
|
* @param targetString - the string in which to search or <code>NULL</code> if youu will
|
|
* set it later by calling <code>setTargetString</code>.
|
|
* @param status - will be set if any errors occur.
|
|
*
|
|
* Note: if on return, status is set to an error code,
|
|
* the only safe thing to do with this object is to call
|
|
* the destructor.
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
BoyerMooreSearch(CollData *theData, const UnicodeString &patternString, const UnicodeString *targetString, UErrorCode &status);
|
|
|
|
/**
|
|
* The desstructor
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
~BoyerMooreSearch();
|
|
|
|
/**
|
|
* Test the pattern to see if it generates any CEs.
|
|
*
|
|
* @return <code>TRUE</code> if the pattern string did not generate any CEs
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
UBool empty();
|
|
|
|
/**
|
|
* Search for the pattern string in the target string.
|
|
*
|
|
* @param offset - the offset in the target string at which to begin the search
|
|
* @param start - will be set to the starting offset of the match, or -1 if there's no match
|
|
* @param end - will be set to the ending offset of the match, or -1 if there's no match
|
|
*
|
|
* @return <code>TRUE</code> if the match succeeds, <code>FALSE</code> otherwise.
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
UBool search(int32_t offset, int32_t &start, int32_t &end);
|
|
|
|
/**
|
|
* Set the target string for the match.
|
|
*
|
|
* @param targetString - the new target string
|
|
* @param status - will be set if any errors occur.
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
void setTargetString(const UnicodeString *targetString, UErrorCode &status);
|
|
|
|
// **** no longer need these? ****
|
|
/**
|
|
* Return the <code>CollData</code> object used for searching
|
|
*
|
|
* @return the <code>CollData</code> object used for searching
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
CollData *getData();
|
|
|
|
/**
|
|
* Return the CEs generated by the pattern string.
|
|
*
|
|
* @return a <code>CEList</code> object holding the CEs generated by the pattern string.
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
CEList *getPatternCEs();
|
|
|
|
/**
|
|
* Return the <code>BadCharacterTable</code> object computed for the pattern string.
|
|
*
|
|
* @return the <code>BadCharacterTable</code> object.
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
BadCharacterTable *getBadCharacterTable();
|
|
|
|
/**
|
|
* Return the <code>GoodSuffixTable</code> object computed for the pattern string.
|
|
*
|
|
* @return the <code>GoodSuffixTable</code> object computed for the pattern string.
|
|
*
|
|
* @internal ICU 4.0.1 technology preview
|
|
*/
|
|
GoodSuffixTable *getGoodSuffixTable();
|
|
|
|
/**
|
|
* UObject glue...
|
|
*/
|
|
virtual UClassID getDynamicClassID() const;
|
|
/**
|
|
* UObject glue...
|
|
*/
|
|
static UClassID getStaticClassID();
|
|
|
|
private:
|
|
CollData *data;
|
|
CEList *patCEs;
|
|
BadCharacterTable *badCharacterTable;
|
|
GoodSuffixTable *goodSuffixTable;
|
|
UnicodeString pattern;
|
|
Target *target;
|
|
};
|
|
|
|
U_NAMESPACE_END
|
|
|
|
#endif // #if !UCONFIG_NO_COLLATION
|
|
#endif // #ifndef B_M_SEARCH_H
|