75f1522155
work to do, but it's about time to give this code more exposure. git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33176 a95241bf-73f2-0310-859d-f6bbb57e9c96
274 lines
8.5 KiB
C
274 lines
8.5 KiB
C
/*
|
|
* Copyright (C) 1996-2009, 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
|
|
|
|
#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.
|
|
*/
|
|
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 */
|