| /* |
| ****************************************************************************** |
| * Copyright (C) 1996-2011, 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; |
| |
| #ifndef U_HIDE_INTERNAL_API |
| /** |
| * 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... |
| * @internal ICU 4.0.1 technology preview |
| */ |
| virtual UClassID getDynamicClassID() const; |
| /** |
| * UObject glue... |
| * @internal ICU 4.0.1 technology preview |
| */ |
| static UClassID getStaticClassID(); |
| |
| private: |
| CollData *data; |
| CEList *patCEs; |
| BadCharacterTable *badCharacterTable; |
| GoodSuffixTable *goodSuffixTable; |
| UnicodeString pattern; |
| Target *target; |
| }; |
| #endif /* U_HIDE_INTERNAL_API */ |
| |
| U_NAMESPACE_END |
| |
| #endif // #if !UCONFIG_NO_COLLATION |
| #endif // #ifndef B_M_SEARCH_H |