| // © 2016 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html |
| /* |
| ********************************************************************** |
| * Copyright (C) 2001-2011 IBM and others. All rights reserved. |
| ********************************************************************** |
| * Date Name Description |
| * 03/22/2000 helena Creation. |
| ********************************************************************** |
| */ |
| |
| #ifndef SEARCH_H |
| #define SEARCH_H |
| |
| #include "unicode/utypes.h" |
| |
| /** |
| * \file |
| * \brief C++ API: SearchIterator object. |
| */ |
| |
| #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION |
| |
| #include "unicode/uobject.h" |
| #include "unicode/unistr.h" |
| #include "unicode/chariter.h" |
| #include "unicode/brkiter.h" |
| #include "unicode/usearch.h" |
| |
| /** |
| * @stable ICU 2.0 |
| */ |
| struct USearch; |
| /** |
| * @stable ICU 2.0 |
| */ |
| typedef struct USearch USearch; |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * |
| * <tt>SearchIterator</tt> is an abstract base class that provides |
| * methods to search for a pattern within a text string. Instances of |
| * <tt>SearchIterator</tt> maintain a current position and scans over the |
| * target text, returning the indices the pattern is matched and the length |
| * of each match. |
| * <p> |
| * <tt>SearchIterator</tt> defines a protocol for text searching. |
| * Subclasses provide concrete implementations of various search algorithms. |
| * For example, <tt>StringSearch</tt> implements language-sensitive pattern |
| * matching based on the comparison rules defined in a |
| * <tt>RuleBasedCollator</tt> object. |
| * <p> |
| * Other options for searching includes using a BreakIterator to restrict |
| * the points at which matches are detected. |
| * <p> |
| * <tt>SearchIterator</tt> provides an API that is similar to that of |
| * other text iteration classes such as <tt>BreakIterator</tt>. Using |
| * this class, it is easy to scan through text looking for all occurances of |
| * a given pattern. The following example uses a <tt>StringSearch</tt> |
| * object to find all instances of "fox" in the target string. Any other |
| * subclass of <tt>SearchIterator</tt> can be used in an identical |
| * manner. |
| * <pre><code> |
| * UnicodeString target("The quick brown fox jumped over the lazy fox"); |
| * UnicodeString pattern("fox"); |
| * |
| * SearchIterator *iter = new StringSearch(pattern, target); |
| * UErrorCode error = U_ZERO_ERROR; |
| * for (int pos = iter->first(error); pos != USEARCH_DONE; |
| * pos = iter->next(error)) { |
| * printf("Found match at %d pos, length is %d\n", pos, |
| * iter.getMatchLength()); |
| * } |
| * </code></pre> |
| * |
| * @see StringSearch |
| * @see RuleBasedCollator |
| */ |
| class U_I18N_API SearchIterator : public UObject { |
| |
| public: |
| |
| // public constructors and destructors ------------------------------- |
| |
| /** |
| * Copy constructor that creates a SearchIterator instance with the same |
| * behavior, and iterating over the same text. |
| * @param other the SearchIterator instance to be copied. |
| * @stable ICU 2.0 |
| */ |
| SearchIterator(const SearchIterator &other); |
| |
| /** |
| * Destructor. Cleans up the search iterator data struct. |
| * @stable ICU 2.0 |
| */ |
| virtual ~SearchIterator(); |
| |
| // public get and set methods ---------------------------------------- |
| |
| /** |
| * Sets the index to point to the given position, and clears any state |
| * that's affected. |
| * <p> |
| * 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. |
| * @param position within the text to be set. If position is less |
| * than or greater than the text range for searching, |
| * an U_INDEX_OUTOFBOUNDS_ERROR will be returned |
| * @param status for errors if it occurs |
| * @stable ICU 2.0 |
| */ |
| virtual void setOffset(int32_t position, UErrorCode &status) = 0; |
| |
| /** |
| * Return the current index in the text being searched. |
| * If the iteration has gone past the end of the text |
| * (or past the beginning for a backwards search), USEARCH_DONE |
| * is returned. |
| * @return current index in the text being searched. |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t getOffset(void) const = 0; |
| |
| /** |
| * 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 attribute text attribute (enum USearchAttribute) to be set |
| * @param value text attribute value |
| * @param status for errors if it occurs |
| * @stable ICU 2.0 |
| */ |
| void setAttribute(USearchAttribute attribute, |
| USearchAttributeValue value, |
| UErrorCode &status); |
| |
| /** |
| * Gets the text searching attributes |
| * @param attribute text attribute (enum USearchAttribute) to be retrieve |
| * @return text attribute value |
| * @stable ICU 2.0 |
| */ |
| USearchAttributeValue getAttribute(USearchAttribute attribute) const; |
| |
| /** |
| * 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 |
| * <tt>first</tt>, <tt>next</tt>, <tt>previous</tt>, or <tt>last</tt>. |
| * Just after construction, or after a searching method returns |
| * <tt>USEARCH_DONE</tt>, this method will return <tt>USEARCH_DONE</tt>. |
| * <p> |
| * Use getMatchedLength to get the matched string length. |
| * @return index of a substring within the text string that is being |
| * searched. |
| * @see #first |
| * @see #next |
| * @see #previous |
| * @see #last |
| * @stable ICU 2.0 |
| */ |
| int32_t getMatchedStart(void) const; |
| |
| /** |
| * 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 <tt>first</tt>, <tt>next</tt>, <tt>previous</tt>, or <tt>last</tt>. |
| * Just after construction, or after a searching method returns |
| * <tt>USEARCH_DONE</tt>, this method will return 0. |
| * @return The length of the match in the target text, or 0 if there |
| * is no match currently. |
| * @see #first |
| * @see #next |
| * @see #previous |
| * @see #last |
| * @stable ICU 2.0 |
| */ |
| int32_t getMatchedLength(void) const; |
| |
| /** |
| * Returns the text that was matched by the most recent call to |
| * <tt>first</tt>, <tt>next</tt>, <tt>previous</tt>, or <tt>last</tt>. |
| * 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. |
| * @param result stores the matched string or an empty string if a match |
| * is not found. |
| * @see #first |
| * @see #next |
| * @see #previous |
| * @see #last |
| * @stable ICU 2.0 |
| */ |
| void getMatchedText(UnicodeString &result) const; |
| |
| /** |
| * Set the BreakIterator that will be used to restrict the points |
| * at which matches are detected. The user is responsible for deleting |
| * the breakiterator. |
| * @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 BreakIterator |
| * @stable ICU 2.0 |
| */ |
| void setBreakIterator(BreakIterator *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>setBreakIterator</tt>. |
| * Note that <tt>NULL</tt> is a legal value; it means that break |
| * detection should not be attempted. |
| * @return BreakIterator used to restrict matchings. |
| * @see #setBreakIterator |
| * @stable ICU 2.0 |
| */ |
| const BreakIterator * getBreakIterator(void) const; |
| |
| /** |
| * 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. The user is responsible for deleting the text. |
| * @param text string to be searched. |
| * @param status for errors. If the text length is 0, |
| * an U_ILLEGAL_ARGUMENT_ERROR is returned. |
| * @stable ICU 2.0 |
| */ |
| virtual void setText(const UnicodeString &text, UErrorCode &status); |
| |
| /** |
| * 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. |
| * <p> |
| * Note: No parsing of the text within the <tt>CharacterIterator</tt> |
| * will be done during searching for this version. The block of text |
| * in <tt>CharacterIterator</tt> will be used as it is. |
| * The user is responsible for deleting the text. |
| * @param text string iterator to be searched. |
| * @param status for errors if any. If the text length is 0 then an |
| * U_ILLEGAL_ARGUMENT_ERROR is returned. |
| * @stable ICU 2.0 |
| */ |
| virtual void setText(CharacterIterator &text, UErrorCode &status); |
| |
| /** |
| * Return the string text to be searched. |
| * @return text string to be searched. |
| * @stable ICU 2.0 |
| */ |
| const UnicodeString & getText(void) const; |
| |
| // operator overloading ---------------------------------------------- |
| |
| /** |
| * Equality operator. |
| * @param that SearchIterator instance to be compared. |
| * @return TRUE if both BreakIterators are of the same class, have the |
| * same behavior, terates over the same text and have the same |
| * attributes. FALSE otherwise. |
| * @stable ICU 2.0 |
| */ |
| virtual UBool operator==(const SearchIterator &that) const; |
| |
| /** |
| * Not-equal operator. |
| * @param that SearchIterator instance to be compared. |
| * @return FALSE if operator== returns TRUE, and vice versa. |
| * @stable ICU 2.0 |
| */ |
| UBool operator!=(const SearchIterator &that) const; |
| |
| // public methods ---------------------------------------------------- |
| |
| /** |
| * Returns a copy of SearchIterator with the same behavior, and |
| * iterating over the same text, as this one. Note that all data will be |
| * replicated, except for the text string to be searched. |
| * @return cloned object |
| * @stable ICU 2.0 |
| */ |
| virtual SearchIterator* safeClone(void) const = 0; |
| |
| /** |
| * 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 <tt>getOffset</tt>) 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 status for errors if it occurs |
| * @return The character index of the first match, or |
| * <tt>USEARCH_DONE</tt> if there are no matches. |
| * @see #getOffset |
| * @stable ICU 2.0 |
| */ |
| int32_t first(UErrorCode &status); |
| |
| /** |
| * Returns the first index equal or 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 <tt>getOffset</tt>) 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 <tt>USEARCH_DONE</tt>. |
| * @param position where search if to start from. If position is less |
| * than or greater than the text range for searching, |
| * an U_INDEX_OUTOFBOUNDS_ERROR will be returned |
| * @param status for errors if it occurs |
| * @return The character index of the first match following |
| * <tt>position</tt>, or <tt>USEARCH_DONE</tt> if there are no |
| * matches. |
| * @see #getOffset |
| * @stable ICU 2.0 |
| */ |
| int32_t following(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 <tt>getOffset</tt>) 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 status for errors if it occurs |
| * @return The index of the first match, or <tt>USEARCH_DONE</tt> if |
| * there are no matches. |
| * @see #getOffset |
| * @stable ICU 2.0 |
| */ |
| int32_t last(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 <tt>getOffset</tt>) 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> |
| * When <tt>USEARCH_OVERLAP</tt> option is off, the last index of the |
| * result match is always less than <tt>position</tt>. |
| * When <tt>USERARCH_OVERLAP</tt> is on, the result match may span across |
| * <tt>position</tt>. |
| * |
| * @param position where search is to start from. If position is less |
| * than or greater than the text range for searching, |
| * an U_INDEX_OUTOFBOUNDS_ERROR will be returned |
| * @param status for errors if it occurs |
| * @return The character index of the first match preceding |
| * <tt>position</tt>, or <tt>USEARCH_DONE</tt> if there are |
| * no matches. |
| * @see #getOffset |
| * @stable ICU 2.0 |
| */ |
| int32_t preceding(int32_t position, UErrorCode &status); |
| |
| /** |
| * Returns the index of the next point at which the text matches the |
| * search pattern, starting from the current position |
| * The iterator is adjusted so that its current index (as returned by |
| * <tt>getOffset</tt>) 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 a position after the end of the text |
| * string. |
| * @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 #getOffset |
| * @stable ICU 2.0 |
| */ |
| int32_t next(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 |
| * <tt>getOffset</tt>) 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 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. |
| * @see #getOffset |
| * @stable ICU 2.0 |
| */ |
| int32_t previous(UErrorCode &status); |
| |
| /** |
| * Resets 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. |
| * @stable ICU 2.0 |
| */ |
| virtual void reset(); |
| |
| protected: |
| // protected data members --------------------------------------------- |
| |
| /** |
| * C search data struct |
| * @stable ICU 2.0 |
| */ |
| USearch *m_search_; |
| |
| /** |
| * Break iterator. |
| * Currently the C++ breakiterator does not have getRules etc to reproduce |
| * another in C. Hence we keep the original around and do the verification |
| * at the end of the match. The user is responsible for deleting this |
| * break iterator. |
| * @stable ICU 2.0 |
| */ |
| BreakIterator *m_breakiterator_; |
| |
| /** |
| * Unicode string version of the search text |
| * @stable ICU 2.0 |
| */ |
| UnicodeString m_text_; |
| |
| // protected constructors and destructors ----------------------------- |
| |
| /** |
| * Default constructor. |
| * Initializes data to the default values. |
| * @stable ICU 2.0 |
| */ |
| SearchIterator(); |
| |
| /** |
| * Constructor for use by subclasses. |
| * @param text The target text to be searched. |
| * @param breakiter A {@link BreakIterator} that is used to restrict the |
| * points at which matches are detected. If |
| * <tt>handleNext</tt> or <tt>handlePrev</tt> finds a |
| * match, but the match's start or end index is not a |
| * boundary as determined by the <tt>BreakIterator</tt>, |
| * the match is rejected and <tt>handleNext</tt> or |
| * <tt>handlePrev</tt> is called again. If this parameter |
| * is <tt>NULL</tt>, no break detection is attempted. |
| * @see #handleNext |
| * @see #handlePrev |
| * @stable ICU 2.0 |
| */ |
| SearchIterator(const UnicodeString &text, |
| BreakIterator *breakiter = NULL); |
| |
| /** |
| * Constructor for use by subclasses. |
| * <p> |
| * Note: No parsing of the text within the <tt>CharacterIterator</tt> |
| * will be done during searching for this version. The block of text |
| * in <tt>CharacterIterator</tt> will be used as it is. |
| * @param text The target text to be searched. |
| * @param breakiter A {@link BreakIterator} that is used to restrict the |
| * points at which matches are detected. If |
| * <tt>handleNext</tt> or <tt>handlePrev</tt> finds a |
| * match, but the match's start or end index is not a |
| * boundary as determined by the <tt>BreakIterator</tt>, |
| * the match is rejected and <tt>handleNext</tt> or |
| * <tt>handlePrev</tt> is called again. If this parameter |
| * is <tt>NULL</tt>, no break detection is attempted. |
| * @see #handleNext |
| * @see #handlePrev |
| * @stable ICU 2.0 |
| */ |
| SearchIterator(CharacterIterator &text, BreakIterator *breakiter = NULL); |
| |
| // protected methods -------------------------------------------------- |
| |
| /** |
| * Assignment operator. Sets this iterator to have the same behavior, |
| * and iterate over the same text, as the one passed in. |
| * @param that instance to be copied. |
| * @stable ICU 2.0 |
| */ |
| SearchIterator & operator=(const SearchIterator &that); |
| |
| /** |
| * Abstract method which subclasses override to provide the mechanism |
| * for finding the next match in the target text. This allows different |
| * subclasses to provide different search algorithms. |
| * <p> |
| * If a match is found, the implementation should return the index at |
| * which the match starts and should call |
| * <tt>setMatchLength</tt> with the number of characters |
| * in the target text that make up the match. If no match is found, the |
| * method should return USEARCH_DONE. |
| * <p> |
| * @param position The index in the target text at which the search |
| * should start. |
| * @param status for error codes if it occurs. |
| * @return index at which the match starts, else if match is not found |
| * USEARCH_DONE is returned |
| * @see #setMatchLength |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t handleNext(int32_t position, UErrorCode &status) |
| = 0; |
| |
| /** |
| * Abstract method which subclasses override to provide the mechanism for |
| * finding the previous match in the target text. This allows different |
| * subclasses to provide different search algorithms. |
| * <p> |
| * If a match is found, the implementation should return the index at |
| * which the match starts and should call |
| * <tt>setMatchLength</tt> with the number of characters |
| * in the target text that make up the match. If no match is found, the |
| * method should return USEARCH_DONE. |
| * <p> |
| * @param position The index in the target text at which the search |
| * should start. |
| * @param status for error codes if it occurs. |
| * @return index at which the match starts, else if match is not found |
| * USEARCH_DONE is returned |
| * @see #setMatchLength |
| * @stable ICU 2.0 |
| */ |
| virtual int32_t handlePrev(int32_t position, UErrorCode &status) |
| = 0; |
| |
| /** |
| * Sets the length of the currently matched string in the text string to |
| * be searched. |
| * Subclasses' <tt>handleNext</tt> and <tt>handlePrev</tt> |
| * methods should call this when they find a match in the target text. |
| * @param length length of the matched text. |
| * @see #handleNext |
| * @see #handlePrev |
| * @stable ICU 2.0 |
| */ |
| virtual void setMatchLength(int32_t length); |
| |
| /** |
| * Sets the offset of the currently matched string in the text string to |
| * be searched. |
| * Subclasses' <tt>handleNext</tt> and <tt>handlePrev</tt> |
| * methods should call this when they find a match in the target text. |
| * @param position start offset of the matched text. |
| * @see #handleNext |
| * @see #handlePrev |
| * @stable ICU 2.0 |
| */ |
| virtual void setMatchStart(int32_t position); |
| |
| /** |
| * sets match not found |
| * @stable ICU 2.0 |
| */ |
| void setMatchNotFound(); |
| }; |
| |
| inline UBool SearchIterator::operator!=(const SearchIterator &that) const |
| { |
| return !operator==(that); |
| } |
| U_NAMESPACE_END |
| |
| #endif /* #if !UCONFIG_NO_COLLATION */ |
| |
| #endif |
| |
