| /* |
| * Copyright (C) 1996-2010, International Business Machines Corporation and Others. |
| * All rights reserved. |
| */ |
| |
| /** |
| * \file |
| * \brief C API: Boyer-Moore StringSearch prototype. |
| * \internal |
| */ |
| |
| #ifndef _BMS_H |
| #define _BMS_H |
| |
| #include "unicode/utypes.h" |
| |
| #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION |
| |
| #include "unicode/ucol.h" |
| |
| /** |
| * A <code>UCD</code> object holds the Collator-specific data needed to |
| * compute the length of the shortest string that can |
| * generate a partcular list of CEs. |
| * |
| * <code>UCD</code> objects are quite expensive to compute. Because |
| * of this, they are cached. When you call <code>ucd_open</code> it |
| * returns a reference counted cached object. When you call <code>ucd_close</code> |
| * the reference count on the object is decremented but the object is not deleted. |
| * |
| * If you do not need to reuse any unreferenced objects in the cache, you can call |
| * <code>ucd_flushCCache</code>. If you no longer need any <code>UCD</code> |
| * objects, you can call <code>ucd_freeCache</code> |
| */ |
| typedef void UCD; |
| |
| /** |
| * Open a <code>UCD</code> object. |
| * |
| * @param coll - the collator |
| * @param status - will be set if any errors occur. |
| * |
| * @return the <code>UCD</code> object. You must call |
| * <code>ucd_close</code> when you are done using the object. |
| * |
| * Note: if on return status is set to an error, the only safe |
| * thing to do with the returned object is to call <code>ucd_close</code>. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI UCD * U_EXPORT2 |
| ucd_open(UCollator *coll, UErrorCode *status); |
| |
| /** |
| * Release a <code>UCD</code> object. |
| * |
| * @param ucd - the object |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI void U_EXPORT2 |
| ucd_close(UCD *ucd); |
| |
| /** |
| * Get the <code>UCollator</code> object used to create a <code>UCD</code> object. |
| * The <code>UCollator</code> object returned may not be the exact |
| * object that was used to create this object, but it will have the |
| * same behavior. |
| * |
| * @param ucd - the <code>UCD</code> object |
| * |
| * @return the <code>UCollator</code> used to create the given |
| * <code>UCD</code> object. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI UCollator * U_EXPORT2 |
| ucd_getCollator(UCD *ucd); |
| |
| /** |
| * <code>UCD</code> objects are expensive to compute, and so |
| * may be cached. This routine will free the cached objects and delete |
| * the cache. |
| * |
| * WARNING: Don't call this until you are have called <code>close</code> |
| * for each <code>UCD</code> object that you have used. also, |
| * DO NOT call this if another thread may be calling <code>ucd_flushCache</code> |
| * at the same time. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI void U_EXPORT2 |
| ucd_freeCache(); |
| |
| /** |
| * <code>UCD</code> objects are expensive to compute, and so |
| * may be cached. This routine will remove any unused <code>UCD</code> |
| * objects from the cache. |
| * |
| * @internal 4.0.1 technology preview |
| */ |
| U_CAPI void U_EXPORT2 |
| ucd_flushCache(); |
| |
| /** |
| * BMS |
| * |
| * 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 first need to get a <code>UCD</code> object by calling <code>ucd_open</code>. |
| * Then you construct a <code>BMS</code> object from the <code>UCD</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, UChar *pattern, int32_t patternLen, UChar *target, int32_t targetLength) |
| * { |
| * UErrorCode status = U_ZERO_ERROR; |
| * int32_t offset = 0, start = -1, end = -1; |
| * UCD *ucd = NULL); |
| * BMS *bms = NULL; |
| * |
| * ucd = ucd_open(collator, &status); |
| * if (U_FAILURE(status)) { |
| * // could not create a UCD object |
| * return; |
| * } |
| * |
| * BMS *bms = bms_open(ucd, pattern, patternLength, target, targetlength, &status); |
| * if (U_FAILURE(status)) { |
| * // could not create a BMS object |
| * ucd_close(ucd); |
| * return; |
| * } |
| * |
| * |
| * // Find all matches |
| * while (bms_search(bms, 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 |
| * } |
| * |
| * bms_close(bms); |
| * ucd_close(ucd); |
| * |
| * // UCD objects are cached, so the call to |
| * // ucd_close doesn't delete the object. |
| * // Call this if you don't need the object any more. |
| * ucd_flushCache(); |
| * } |
| * </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.) |
| * |
| * NOTE: This is a technology preview. The final version of this API may not bear any resenblence to this API. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| struct BMS; |
| typedef struct BMS BMS; /**< @see BMS */ |
| |
| /** |
| * Construct a <code>MBS</code> object. |
| * |
| * @param ucd - A <code>UCD</code> object holding the Collator-sensitive data |
| * @param pattern - the string for which to search |
| * @param patternLength - the length of the string for which to search |
| * @param target - the string in which to search |
| * @param targetLength - the length of the string in which to search |
| * @param status - will be set if any errors occur. |
| * |
| * @return the <code>BMS</code> object. |
| * |
| * Note: if on return status is set to an error, the only safe |
| * thing to do with the returned object is to call |
| * <code>bms_close</code>. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI BMS * U_EXPORT2 |
| bms_open(UCD *ucd, |
| const UChar *pattern, int32_t patternLength, |
| const UChar *target, int32_t targetLength, |
| UErrorCode *status); |
| |
| /** |
| * Close a <code>BMS</code> object and release all the |
| * storage associated with it. |
| * |
| * @param bms - the <code>BMS</code> object to close. |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI void U_EXPORT2 |
| bms_close(BMS *bms); |
| |
| /** |
| * Test the pattern to see if it generates any CEs. |
| * |
| * @param bms - the <code>BMS</code> object |
| * @return <code>TRUE</code> if the pattern string did not generate any CEs |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI UBool U_EXPORT2 |
| bms_empty(BMS *bms); |
| |
| /** |
| * Get the <code>UCD</code> object used to create |
| * a given <code>BMS</code> object. |
| * |
| * @param bms - the <code>BMS</code> object |
| * |
| * @return - the <code>UCD</code> object used to create |
| * the given <code>BMS</code> object. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI UCD * U_EXPORT2 |
| bms_getData(BMS *bms); |
| |
| /** |
| * Search for the pattern string in the target string. |
| * |
| * @param bms - the <code>BMS</code> object |
| * @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 |
| */ |
| U_CAPI UBool U_EXPORT2 |
| bms_search(BMS *bms, int32_t offset, int32_t *start, int32_t *end); |
| |
| /** |
| * Set the target string for the match. |
| * |
| * @param bms - the <code>BMS</code> object |
| * @param target - the new target string |
| * @param targetLength - the length of the new target string |
| * @param status - will be set if any errors occur. |
| * |
| * @internal ICU 4.0.1 technology preview |
| */ |
| U_CAPI void U_EXPORT2 |
| bms_setTargetString(BMS *bms, const UChar *target, int32_t targetLength, UErrorCode *status); |
| |
| #endif |
| |
| #endif /* _BMS_H */ |