| /* |
| ********************************************************************** |
| * Copyright (C) 2001 IBM and others. All rights reserved. |
| ********************************************************************** |
| * Date Name Description |
| * 06/28/2001 synwee Creation. |
| ********************************************************************** |
| */ |
| #ifndef USEARCH_H |
| #define USEARCH_H |
| |
| #include "unicode/utypes.h" |
| #include "unicode/ucol.h" |
| #include "unicode/ucoleitr.h" |
| #include "unicode/ubrk.h" |
| |
| /** |
| * C Apis for an engine that provides language-sensitive text searching based |
| * on the comparison rules defined in a <tt>UCollator</tt> data struct, |
| * see <tt>ucol.h</tt>. This ensures that language eccentricity can be |
| * handled, e.g. for the German collator, characters ß and SS will be matched |
| * if case is chosen to be ignored. |
| * See the <a href=http://oss.software.ibm.com/icu/develop/collation/ICU_collation_design.htm> |
| * "ICU Collation Design Document"</a> for more information. |
| * <p> |
| * The algorithm implemented is a modified form of the Boyer Moore's search. |
| * For more information see |
| * <a href=http://oss.software.ibm.com/icu/docs/papers/text-search.html> |
| * "Efficient Text Searching in Java"</a>, published in <i>Java Report</i> |
| * in February, 1999, for further information on the algorithm. |
| * <p> |
| * There are 2 match options for selection:<br> |
| * Let S' be the sub-string of a text string S between the offsets start and |
| * end <start, end>. |
| * <br> |
| * A pattern string P matches a text string S at the offsets <start, end> |
| * if |
| * <pre> |
| * option 1. Some canonical equivalent of P matches some canonical equivalent |
| * of S' |
| * option 2. P matches S' and if P starts or ends with a combining mark, |
| * there exists no non-ignorable combining mark before or after S |
| * in S respectively. |
| * </pre> |
| * Option 2. will be the default· |
| * <p> |
| * This search has APIs similar to that of other text iteration mechanisms |
| * such as the break iterators in <tt>ubrk.h</tt>. Using these |
| * APIs, it is easy to scan through text looking for all occurances of |
| * a given pattern. This search iterator allows changing of direction by |
| * calling a <tt>reset</tt> followed by a <tt>next</tt> or <tt>previous</tt>. |
| * Though a direction change can occur without calling <tt>reset</tt> first, |
| * this operation comes with some speed penalty. |
| * Generally, match results in the forward direction will match the result |
| * matches in the backwards direction in the reverse order |
| * <p> |
| * <tt>usearch.h</tt> provides APIs to specify the starting position |
| * within the text string to be searched, e.g. <tt>usearch_setOffset</tt>, |
| * <tt>usearch_preceding</tt> and <tt>usearch_following</tt>. Since the |
| * starting position will be set as it is specified, please take note that |
| * there are some dangerous positions which the search may render incorrect |
| * results: |
| * <ul> |
| * <li> The midst of a substring that requires normalization. |
| * <li> If the following match is to be found, the position should not be the |
| * second character which requires to be swapped with the preceding |
| * character. Vice versa, if the preceding match is to be found, |
| * position to search from should not be the first character which |
| * requires to be swapped with the next character. E.g certain Thai and |
| * Lao characters require swapping. |
| * <li> If a following pattern match is to be found, any position within a |
| * contracting sequence except the first will fail. Vice versa if a |
| * preceding pattern match is to be found, a invalid starting point |
| * would be any character within a contracting sequence except the last. |
| * <\ul> |
| * <p> |
| * A breakiterator can be used if only matches at logical breaks are desired. |
| * Using a breakiterator will only give you results that exactly matches the |
| * boundaries given by the breakiterator. For instance the pattern "e" will |
| * not be found in the string "\u00e9" if a character break iterator is used. |
| * <p> |
| * Options are provided to handle overlapping matches. |
| * E.g. In English, overlapping matches produces the result 0 and 2 |
| * for the pattern "abab" in the text "ababab", where else mutually |
| * exclusive matches only produce the result of 0. |
| * <p> |
| * Though collator attributes will be taken into consideration while |
| * performing matches, there are no APIs here for setting and getting the |
| * attributes. These attributes can be set by getting the collator |
| * from <tt>usearch_getCollator</tt> and using the APIs in <tt>ucol.h</tt>. |
| * Lastly to update String Search to the new collator attributes, |
| * usearch_reset() has to be called. |
| * <p> |
| * Restriction: <br> |
| * Currently there are no composite characters that consists of a |
| * character with combining class > 0 before a character with combining |
| * class == 0. However, if such a character exists in the future, the |
| * search mechanism does not guarantee the results for option 1. |
| * |
| * <p> |
| * Example of use:<br> |
| * <pre><code> |
| * char *tgtstr = "The quick brown fox jumped over the lazy fox"; |
| * char *patstr = "fox"; |
| * UChar target[64]; |
| * UChar pattern[16]; |
| * UErrorCode status = U_ZERO_ERROR; |
| * u_uastrcpy(target, tgtstr); |
| * u_uastrcpy(pattern, patstr); |
| * |
| * UStringSearch *search = usearch_open(pattern, -1, target, -1, "en_US", |
| * &status); |
| * if (U_SUCCESS(status)) { |
| * for (int pos = usearch_first(search, &status); |
| * pos != USEARCH_DONE; |
| * pos = usearch_next(search, &status)) { |
| * printf("Found match at %d pos, length is %d\n", pos, |
| * usearch_getMatchLength(search)); |
| * } |
| * } |
| * </code></pre> |
| * @since ICU 2.0 |
| */ |
| |
| /** |
| * DONE is returned by previous() and next() after all valid matches have |
| * been returned, and by first() and last() if there are no matches at all. |
| */ |
| #define USEARCH_DONE -1 |
| |
| /** |
| * Data structure for searching |
| */ |
| struct UStringSearch; |
| typedef struct UStringSearch UStringSearch; |
| |
| typedef enum { |
| /** Option for overlapping matches */ |
| USEARCH_OVERLAP, |
| /** |
| Option for canonical matches. option 1 in header documentation. |
| The default value will be USEARCH_OFF |
| */ |
| USEARCH_CANONICAL_MATCH, |
| USEARCH_ATTRIBUTE_COUNT |
| } USearchAttribute; |
| |
| typedef enum { |
| /** default value for any USearchAttribute */ |
| USEARCH_DEFAULT = -1, |
| /** value for USEARCH_OVERLAP and USEARCH_CANONICAL_MATCH */ |
| USEARCH_OFF, |
| /** value for USEARCH_OVERLAP and USEARCH_CANONICAL_MATCH */ |
| USEARCH_ON, |
| USEARCH_ATTRIBUTE_VALUE_COUNT |
| } USearchAttributeValue; |
| |
| /* open and close ------------------------------------------------------ */ |
| |
| /** |
| * Creating a search iterator data struct using the argument locale language |
| * rule set. A collator will be created in the process, which will be owned by |
| * this search and will be deleted in <tt>usearch_close</tt>. |
| * @param pattern for matching |
| * @param patternlength length of the pattern, -1 for null-termination |
| * @param text text string |
| * @param textlength length of the text string, -1 for null-termination |
| * @param locale name of locale for the rules to be used |
| * @param breakiter A BreakIterator that will be used to restrict the points |
| * at which matches are detected. If a match is found, but |
| * the match's start or end index is not a boundary as |
| * determined by the <tt>BreakIterator</tt>, the match will |
| * be rejected and another will be searched for. |
| * If this parameter is <tt>NULL</tt>, no break detection is |
| * attempted. |
| * @param status for errors if it occurs. If pattern or text is NULL, or if |
| * patternlength or textlength is 0 then an |
| * U_ILLEGAL_ARGUMENT_ERROR is returned. |
| * @return search iterator data structure, or NULL if there is an error. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI UStringSearch * U_EXPORT2 usearch_open(const UChar *pattern, |
| int32_t patternlength, |
| const UChar *text, |
| int32_t textlength, |
| const char *locale, |
| UBreakIterator *breakiter, |
| UErrorCode *status); |
| |
| /** |
| * Creating a search iterator data struct using the argument collator language |
| * rule set. Note, user retains the ownership of this collator, thus the |
| * responsibility of deletion lies with the user. |
| * @param pattern for matching |
| * @param patternlength length of the pattern, -1 for null-termination |
| * @param text text string |
| * @param textlength length of the text string, -1 for null-termination |
| * @param collator used for the language rules |
| * @param breakiter A BreakIterator that will be used to restrict the points |
| * at which matches are detected. If a match is found, but |
| * the match's start or end index is not a boundary as |
| * determined by the <tt>BreakIterator</tt>, the match will |
| * be rejected and another will be searched for. |
| * If this parameter is <tt>NULL</tt>, no break detection is |
| * attempted. |
| * @param status for errors if it occurs. If collator, pattern or text is NULL, |
| * or if patternlength or textlength is 0 then an |
| * U_ILLEGAL_ARGUMENT_ERROR is returned. |
| * @return search iterator data structure, or NULL if there is an error. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI UStringSearch * U_EXPORT2 usearch_openFromCollator( |
| const UChar *pattern, |
| int32_t patternlength, |
| const UChar *text, |
| int32_t textlength, |
| const UCollator *collator, |
| UBreakIterator *breakiter, |
| UErrorCode *status); |
| |
| /** |
| * Destroying and cleaning up the search iterator data struct. |
| * If a collator is created in usearch_open, it will be destroyed here. |
| * @param searchiter data struct to clean up |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_close(UStringSearch *strsrch); |
| |
| /* get and set methods -------------------------------------------------- */ |
| |
| /** |
| * Sets the current position in the text string which the next search will |
| * start from. Clears previous states. |
| * This method takes the argument index and sets the position in the text |
| * string accordingly without checking if the index is pointing to a |
| * valid starting point to begin searching. |
| * Search positions that may render incorrect results are highlighted in the |
| * header comments |
| * @param strsrch search iterator data struct |
| * @param position position to start next search from. If position is less |
| * than or greater than the text range for searching, |
| * an U_INDEX_OUTOFBOUNDS_ERROR will be returned |
| * @param status error status if any. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_setOffset(UStringSearch *strsrch, |
| int32_t position, |
| UErrorCode *status); |
| |
| /** |
| * Return the current index in the string text being searched. |
| * If the iteration has gone past the end of the text (or past the beginning |
| * for a backwards search), {@link #USEARCH_DONE} is returned. |
| * @param strsrch search iterator data struct |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_getOffset(const UStringSearch *strsrch); |
| |
| /** |
| * Sets the text searching attributes located in the enum USearchAttribute |
| * with values from the enum USearchAttributeValue. |
| * USEARCH_DEFAULT can be used for all attributes for resetting. |
| * @param strsrch search iterator data struct |
| * @param attribute text attribute to be set |
| * @param value text attribute value |
| * @param status for errors if it occurs |
| * @see #usearch_getAttribute |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_setAttribute(UStringSearch *strsrch, |
| USearchAttribute attribute, |
| USearchAttributeValue value, |
| UErrorCode *status); |
| |
| /** |
| * Gets the text searching attributes. |
| * @param strsrch search iterator data struct |
| * @param attribute text attribute to be retrieve |
| * @return text attribute value |
| * @see #usearch_setAttribute |
| * @draft ICU 2.0 |
| */ |
| U_CAPI USearchAttributeValue U_EXPORT2 usearch_getAttribute( |
| const UStringSearch *strsrch, |
| USearchAttribute attribute); |
| |
| /** |
| * Returns the index to the match in the text string that was searched. |
| * This call returns a valid result only after a successful call to |
| * {@link #usearch_first}, {@link #usearch_next}, |
| * {@link #usearch_previous}, or {@link #usearch_last}. |
| * Just after construction, or after a searching method returns |
| * <tt>USEARCH_DONE</tt>, this method will return <tt>USEARCH_DONE</tt>. |
| * <p> |
| * Use usearch_getMatchedLength to get the matched string length. |
| * @param strsrch search iterator data struct |
| * @return index to a substring within the text string that is being |
| * searched. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_getMatchedStart( |
| const UStringSearch *strsrch); |
| |
| /** |
| * Returns the length of text in the string which matches the search pattern. |
| * This call returns a valid result only after a successful call to |
| * {@link #usearch_first}, {@link #usearch_next}, |
| * {@link #usearch_previous}, or {@link #usearch_last}. |
| * Just after construction, or after a searching method returns |
| * <tt>USEARCH_DONE</tt>, this method will return 0. |
| * @param strsrch search iterator data struct |
| * @return The length of the match in the string text, or 0 if there is no |
| * match currently. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_getMatchedLength( |
| const UStringSearch *strsrch); |
| |
| /** |
| * Returns the text that was matched by the most recent call to |
| * {@link #usearch_first}, {@link #usearch_next}, |
| * {@link #usearch_previous}, or {@link #usearch_last}. |
| * If the iterator is not pointing at a valid match (e.g. just after |
| * construction or after <tt>USEARCH_DONE</tt> has been returned, returns |
| * an empty string. If result is not large enough to store the matched text, |
| * result will be filled with the partial text and an U_BUFFER_OVERFLOW_ERROR |
| * will be returned in status. result will be null-terminated whenever |
| * possible. If the buffer fits the matched text exactly, a null-termination |
| * is not possible, then a U_STRING_NOT_TERMINATED_ERROR set in status. |
| * Pre-flighting can be either done with length = 0 or the API |
| * usearch_getMatchLength(). |
| * @param strsrch search iterator data struct |
| * @param result UChar buffer to store the matched string |
| * @param resultCapacity length of the result buffer |
| * @param status error returned if result is not large enough |
| * @return exact length of the matched text, not counting the null-termination |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_getMatchedText(const UStringSearch *strsrch, |
| UChar *result, |
| int32_t resultCapacity, |
| UErrorCode *status); |
| |
| /** |
| * Set the BreakIterator that will be used to restrict the points at which |
| * matches are detected. |
| * @param strsrch search iterator data struct |
| * @param breakiter A BreakIterator that will be used to restrict the points |
| * at which matches are detected. If a match is found, but |
| * the match's start or end index is not a boundary as |
| * determined by the <tt>BreakIterator</tt>, the match will |
| * be rejected and another will be searched for. |
| * If this parameter is <tt>NULL</tt>, no break detection is |
| * attempted. |
| * @param status for errors if it occurs |
| * @see #usearch_getBreakIterator |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_setBreakIterator(UStringSearch *strsrch, |
| UBreakIterator *breakiter, |
| UErrorCode *status); |
| |
| /** |
| * Returns the BreakIterator that is used to restrict the points at which |
| * matches are detected. This will be the same object that was passed to the |
| * constructor or to <tt>usearch_setBreakIterator</tt>. Note that |
| * <tt>NULL</tt> |
| * is a legal value; it means that break detection should not be attempted. |
| * @param strsrch search iterator data struct |
| * @return break iterator used |
| * @see #usearch_setBreakIterator |
| * @draft ICU 2.0 |
| */ |
| U_CAPI const UBreakIterator * U_EXPORT2 usearch_getBreakIterator( |
| const UStringSearch *strsrch); |
| |
| /** |
| * Set the string text to be searched. Text iteration will hence begin at the |
| * start of the text string. This method is useful if you want to re-use an |
| * iterator to search for the same pattern within a different body of text. |
| * @param strsrch search iterator data struct |
| * @param text new string to look for match |
| * @param textlength length of the new string, -1 for null-termination |
| * @param status for errors if it occurs. If text is NULL, or textlength is 0 |
| * then an U_ILLEGAL_ARGUMENT_ERROR is returned with no change |
| * done to strsrch. |
| * @see #usearch_getText |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_setText( UStringSearch *strsrch, |
| const UChar *text, |
| int32_t textlength, |
| UErrorCode *status); |
| |
| /** |
| * Return the string text to be searched. |
| * @param strsrch search iterator data struct |
| * @param length returned string text length |
| * @return string text |
| * @see #usearch_setText |
| * @draft ICU 2.0 |
| */ |
| U_CAPI const UChar * U_EXPORT2 usearch_getText(const UStringSearch *strsrch, |
| int32_t *length); |
| |
| /** |
| * Gets the collator used for the language rules. |
| * <p> |
| * Deleting the returned <tt>UCollator</tt> before calling |
| * <tt>usearch_close</tt> would cause the string search to fail. |
| * <tt>usearch_close</tt> will delete the collator if this search owns it. |
| * @param strsrch search iterator data struct |
| * @return collator |
| * @draft ICU 2.0 |
| */ |
| U_CAPI UCollator * U_EXPORT2 usearch_getCollator( |
| const UStringSearch *strsrch); |
| |
| /** |
| * Sets the collator used for the language rules. User retains the ownership |
| * of this collator, thus the responsibility of deletion lies with the user. |
| * This method causes internal data such as Boyer-Moore shift tables to |
| * be recalculated, but the iterator's position is unchanged. |
| * @param strsrch search iterator data struct |
| * @param collator to be used |
| * @param status for errors if it occurs |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_setCollator( UStringSearch *strsrch, |
| const UCollator *collator, |
| UErrorCode *status); |
| |
| /** |
| * Sets the pattern used for matching. |
| * Internal data like the Boyer Moore table will be recalculated, but the |
| * iterator's position is unchanged. |
| * @param strsrch search iterator data struct |
| * @param pattern string |
| * @param patternlength pattern length, -1 for null-terminated string |
| * @param status for errors if it occurs. If text is NULL, or textlength is 0 |
| * then an U_ILLEGAL_ARGUMENT_ERROR is returned with no change |
| * done to strsrch. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_setPattern( UStringSearch *strsrch, |
| const UChar *pattern, |
| int32_t patternlength, |
| UErrorCode *status); |
| |
| /** |
| * Gets the search pattern |
| * @param strsrch search iterator data struct |
| * @param length return length of the pattern, -1 indicates that the pattern |
| * is null-terminated |
| * @return pattern string |
| * @draft ICU 2.0 |
| */ |
| U_CAPI const UChar * U_EXPORT2 usearch_getPattern( |
| const UStringSearch *strsrch, |
| int32_t *length); |
| |
| /* methods ------------------------------------------------------------- */ |
| |
| /** |
| * Returns the first index at which the string text matches the search |
| * pattern. |
| * The iterator is adjusted so that its current index (as returned by |
| * {@link #usearch_getOffset}) is the match position if one was found. |
| * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and |
| * the iterator will be adjusted to the index USEARCH_DONE. |
| * @param strsrch search iterator data struct |
| * @param status for errors if it occurs |
| * @return The character index of the first match, or |
| * <tt>USEARCH_DONE</tt> if there are no matches. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_first(UStringSearch *strsrch, |
| UErrorCode *status); |
| |
| /** |
| * Returns the first index greater than <tt>position</tt> at which the string |
| * text |
| * matches the search pattern. The iterator is adjusted so that its current |
| * index (as returned by {@link #usearch_getOffset}) is the match position if |
| * one was found. |
| * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and |
| * the iterator will be adjusted to the index USEARCH_DONE |
| * <p> |
| * Search positions that may render incorrect results are highlighted in the |
| * header comments. If position is less than or greater than the text range |
| * for searching, an U_INDEX_OUTOFBOUNDS_ERROR will be returned |
| * @param strsrch search iterator data struct |
| * @param position to start the search at |
| * @param status for errors if it occurs |
| * @return The character index of the first match following <tt>pos</tt>, |
| * or <tt>USEARCH_DONE</tt> if there are no matches. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_following(UStringSearch *strsrch, |
| int32_t position, |
| UErrorCode *status); |
| |
| /** |
| * Returns the last index in the target text at which it matches the search |
| * pattern. The iterator is adjusted so that its current |
| * index (as returned by {@link #usearch_getOffset}) is the match position if |
| * one was found. |
| * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and |
| * the iterator will be adjusted to the index USEARCH_DONE. |
| * @param strsrch search iterator data struct |
| * @param status for errors if it occurs |
| * @return The index of the first match, or <tt>USEARCH_DONE</tt> if there |
| * are no matches. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_last(UStringSearch *strsrch, |
| UErrorCode *status); |
| |
| /** |
| * Returns the first index less than <tt>position</tt> at which the string text |
| * matches the search pattern. The iterator is adjusted so that its current |
| * index (as returned by {@link #usearch_getOffset}) is the match position if |
| * one was found. |
| * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and |
| * the iterator will be adjusted to the index USEARCH_DONE |
| * <p> |
| * Search positions that may render incorrect results are highlighted in the |
| * header comments. If position is less than or greater than the text range |
| * for searching, an U_INDEX_OUTOFBOUNDS_ERROR will be returned |
| * @param strsrch search iterator data struct |
| * @param position index position the search is to begin at |
| * @param status for errors if it occurs |
| * @return The character index of the first match preceding <tt>pos</tt>, |
| * or <tt>USEARCH_DONE</tt> if there are no matches. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_preceding(UStringSearch *strsrch, |
| int32_t position, |
| UErrorCode *status); |
| |
| /** |
| * Returns the index of the next point at which the string text matches the |
| * search pattern, starting from the current position. |
| * The iterator is adjusted so that its current |
| * index (as returned by {@link #usearch_getOffset}) is the match position if |
| * one was found. |
| * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and |
| * the iterator will be adjusted to the index USEARCH_DONE |
| * @param strsrch search iterator data struct |
| * @param status for errors if it occurs |
| * @return The index of the next match after the current position, or |
| * <tt>USEARCH_DONE</tt> if there are no more matches. |
| * @see #usearch_first |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_next(UStringSearch *strsrch, |
| UErrorCode *status); |
| |
| /** |
| * Returns the index of the previous point at which the string text matches |
| * the search pattern, starting at the current position. |
| * The iterator is adjusted so that its current |
| * index (as returned by {@link #usearch_getOffset}) is the match position if |
| * one was found. |
| * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and |
| * the iterator will be adjusted to the index USEARCH_DONE |
| * @param strsrch search iterator data struct |
| * @param status for errors if it occurs |
| * @return The index of the previous match before the current position, |
| * or <tt>USEARCH_DONE</tt> if there are no more matches. |
| * @draft ICU 2.0 |
| */ |
| U_CAPI int32_t U_EXPORT2 usearch_previous(UStringSearch *strsrch, |
| UErrorCode *status); |
| |
| /** |
| * Reset the iteration. |
| * Search will begin at the start of the text string if a forward iteration |
| * is initiated before a backwards iteration. Otherwise if a backwards |
| * iteration is initiated before a forwards iteration, the search will begin |
| * at the end of the text string. |
| * @param strsrch search iterator data struct |
| * @draft ICU 2.0 |
| */ |
| U_CAPI void U_EXPORT2 usearch_reset(UStringSearch *strsrch); |
| |
| #endif |
| |
| |
