The Tor Browser: intl/icu/source/i18n/unicode/stsearch.h@fc2d59ddac77 (annotated)

intl/icu/source/i18n/unicode/stsearch.h@fc2d59ddac77 (annotated)

intl/icu/source/i18n/unicode/stsearch.h

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /*
 **********************************************************************
 *   Copyright (C) 2001-2008 IBM and others. All rights reserved.
 **********************************************************************
 *   Date        Name        Description
 *  03/22/2000   helena      Creation.
 **********************************************************************
 */
 #ifndef STSEARCH_H
 #define STSEARCH_H
 #include "unicode/utypes.h"
 /**
  * \file
  * \brief C++ API: Service for searching text based on RuleBasedCollator.
  */
 #if !UCONFIG_NO_COLLATION && !UCONFIG_NO_BREAK_ITERATION
 #include "unicode/tblcoll.h"
 #include "unicode/coleitr.h"
 #include "unicode/search.h"
 U_NAMESPACE_BEGIN
 /**
  *
  * <tt>StringSearch</tt> is a <tt>SearchIterator</tt> that provides
  * language-sensitive text searching based on the comparison rules defined
  * in a {@link RuleBasedCollator} object.
  * StringSearch ensures that language eccentricity can be
  * handled, e.g. for the German collator, characters &szlig; and SS will be matched
  * if case is chosen to be ignored.
  * See the <a href="http://source.icu-project.org/repos/icu/icuhtml/trunk/design/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://icu-project.org/docs/papers/efficient_text_searching_in_java.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>BreakIterator</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.
  * Match results in the forward direction will match the result matches in
  * the backwards direction in the reverse order
  * <p>
  * <tt>SearchIterator</tt> provides APIs to specify the starting position
  * within the text string to be searched, e.g. <tt>setOffset</tt>,
  * <tt>preceding</tt> and <tt>following</tt>. Since the
  * starting position will be set as it is specified, please take note that
  * there are some danger points 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>getCollator</tt> and using the APIs in <tt>coll.h</tt>.
  * Lastly to update StringSearch to the new collator attributes,
  * 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,
  * StringSearch does not guarantee the results for option 1.
  * <p>
  * Consult the <tt>SearchIterator</tt> documentation for information on
  * and examples of how to use instances of this class to implement text
  * searching.
  * <pre><code>
  * UnicodeString target("The quick brown fox jumps over the lazy dog.");
  * UnicodeString pattern("fox");
  *
  * UErrorCode      error = U_ZERO_ERROR;
  * StringSearch iter(pattern, target, Locale::getUS(), NULL, status);
  * 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>
  * <p>
  * Note, StringSearch is not to be subclassed.
  * </p>
  * @see SearchIterator
  * @see RuleBasedCollator
  * @since ICU 2.0
  */
 class U_I18N_API StringSearch : public SearchIterator
 {
 public:
     // public constructors and destructors --------------------------------
     /**
      * Creating a <tt>StringSearch</tt> instance using the argument locale
      * language rule set. A collator will be created in the process, which
      * will be owned by this instance and will be deleted during
      * destruction
      * @param pattern The text for which this object will search.
      * @param text    The text in which to search for the pattern.
      * @param locale  A locale which defines the language-sensitive
      *                comparison rules used to determine whether text in the
      *                pattern and target matches.
      * @param breakiter A <tt>BreakIterator</tt> object used to constrain
      *                the matches that are found. Matches whose start and end
      *                indices in the target text are not boundaries as
      *                determined by the <tt>BreakIterator</tt> are
      *                ignored. If this behavior is not desired,
      *                <tt>NULL</tt> can be passed in instead.
      * @param status  for errors if any. If pattern or text is NULL, or if
      *               either the length of pattern or text is 0 then an
      *               U_ILLEGAL_ARGUMENT_ERROR is returned.
      * @stable ICU 2.0
      */
     StringSearch(const UnicodeString &pattern, const UnicodeString &text,
                  const Locale        &locale,
                        BreakIterator *breakiter,
                        UErrorCode    &status);
     /**
      * Creating a <tt>StringSearch</tt> instance using the argument collator
      * language rule set. Note, user retains the ownership of this collator,
      * it does not get destroyed during this instance's destruction.
      * @param pattern The text for which this object will search.
      * @param text    The text in which to search for the pattern.
      * @param coll    A <tt>RuleBasedCollator</tt> object which defines
      *                the language-sensitive comparison rules used to
      *                determine whether text in the pattern and target
      *                matches. User is responsible for the clearing of this
      *                object.
      * @param breakiter A <tt>BreakIterator</tt> object used to constrain
      *                the matches that are found. Matches whose start and end
      *                indices in the target text are not boundaries as
      *                determined by the <tt>BreakIterator</tt> are
      *                ignored. If this behavior is not desired,
      *                <tt>NULL</tt> can be passed in instead.
      * @param status for errors if any. If either the length of pattern or
      *               text is 0 then an U_ILLEGAL_ARGUMENT_ERROR is returned.
      * @stable ICU 2.0
      */
     StringSearch(const UnicodeString     &pattern,
                  const UnicodeString     &text,
                        RuleBasedCollator *coll,
                        BreakIterator     *breakiter,
                        UErrorCode        &status);
     /**
      * Creating a <tt>StringSearch</tt> instance using the argument locale
      * language rule set. A collator will be created in the process, which
      * will be owned by this instance and will be deleted during
      * destruction
      * <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 pattern The text for which this object will search.
      * @param text    The text iterator in which to search for the pattern.
      * @param locale  A locale which defines the language-sensitive
      *                comparison rules used to determine whether text in the
      *                pattern and target matches. User is responsible for
      *                the clearing of this object.
      * @param breakiter A <tt>BreakIterator</tt> object used to constrain
      *                the matches that are found. Matches whose start and end
      *                indices in the target text are not boundaries as
      *                determined by the <tt>BreakIterator</tt> are
      *                ignored. If this behavior is not desired,
      *                <tt>NULL</tt> can be passed in instead.
      * @param status for errors if any. If either the length of pattern or
      *               text is 0 then an U_ILLEGAL_ARGUMENT_ERROR is returned.
      * @stable ICU 2.0
      */
     StringSearch(const UnicodeString &pattern, CharacterIterator &text,
                  const Locale        &locale,
                        BreakIterator *breakiter,
                        UErrorCode    &status);
     /**
      * Creating a <tt>StringSearch</tt> instance using the argument collator
      * language rule set. Note, user retains the ownership of this collator,
      * it does not get destroyed during this instance's destruction.
      * <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 pattern The text for which this object will search.
      * @param text    The text in which to search for the pattern.
      * @param coll    A <tt>RuleBasedCollator</tt> object which defines
      *                the language-sensitive comparison rules used to
      *                determine whether text in the pattern and target
      *                matches. User is responsible for the clearing of this
      *                object.
      * @param breakiter A <tt>BreakIterator</tt> object used to constrain
      *                the matches that are found. Matches whose start and end
      *                indices in the target text are not boundaries as
      *                determined by the <tt>BreakIterator</tt> are
      *                ignored. If this behavior is not desired,
      *                <tt>NULL</tt> can be passed in instead.
      * @param status for errors if any. If either the length of pattern or
      *               text is 0 then an U_ILLEGAL_ARGUMENT_ERROR is returned.
      * @stable ICU 2.0
      */
     StringSearch(const UnicodeString     &pattern, CharacterIterator &text,
                        RuleBasedCollator *coll,
                        BreakIterator     *breakiter,
                        UErrorCode        &status);
     /**
      * Copy constructor that creates a StringSearch instance with the same
      * behavior, and iterating over the same text.
      * @param that StringSearch instance to be copied.
      * @stable ICU 2.0
      */
     StringSearch(const StringSearch &that);
     /**
     * Destructor. Cleans up the search iterator data struct.
     * If a collator is created in the constructor, it will be destroyed here.
     * @stable ICU 2.0
     */
     virtual ~StringSearch(void);
     /**
      * Clone this object.
      * Clones can be used concurrently in multiple threads.
      * If an error occurs, then NULL is returned.
      * The caller must delete the clone.
      *
      * @return a clone of this object
      *
      * @see getDynamicClassID
      * @stable ICU 2.8
      */
     StringSearch *clone() const;
     // operator overloading ---------------------------------------------
     /**
      * 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
      */
     StringSearch & operator=(const StringSearch &that);
     /**
      * Equality operator.
      * @param that instance to be compared.
      * @return TRUE if both instances have the same attributes,
      *         breakiterators, collators and iterate over the same text
      *         while looking for the same pattern.
      * @stable ICU 2.0
      */
     virtual UBool operator==(const SearchIterator &that) const;
     // 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);
     /**
      * 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;
     /**
      * Set the target 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 text text string 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(const UnicodeString &text, UErrorCode &status);
     /**
      * Set the target 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.
      * 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 text string 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);
     /**
      * Gets the collator used for the language rules.
      * <p>
      * Caller may modify but <b>must not</b> delete the <tt>RuleBasedCollator</tt>!
      * Modifications to this collator will affect the original collator passed in to
      * the <tt>StringSearch></tt> constructor or to setCollator, if any.
      * @return collator used for string search
      * @stable ICU 2.0
      */
     RuleBasedCollator * getCollator() const;
     /**
      * 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 coll    collator
      * @param status  for errors if any
      * @stable ICU 2.0
      */
     void setCollator(RuleBasedCollator *coll, 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 pattern search pattern to be found
      * @param status for errors if any. If the pattern length is 0 then an
      *               U_ILLEGAL_ARGUMENT_ERROR is returned.
      * @stable ICU 2.0
      */
     void setPattern(const UnicodeString &pattern, UErrorCode &status);
     /**
      * Gets the search pattern.
      * @return pattern used for matching
      * @stable ICU 2.0
      */
     const UnicodeString & getPattern() const;
     // public methods ----------------------------------------------------
     /**
      * 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.
      * @stable ICU 2.0
      */
     virtual void reset();
     /**
      * Returns a copy of StringSearch with the same behavior, and
      * iterating over the same text, as this one. Note that all data will be
      * replicated, except for the user-specified collator and the
      * breakiterator.
      * @return cloned object
      * @stable ICU 2.0
      */
     virtual SearchIterator * safeClone(void) const;
     /**
      * ICU "poor man's RTTI", returns a UClassID for the actual class.
      *
      * @stable ICU 2.2
      */
     virtual UClassID getDynamicClassID() const;
     /**
      * ICU "poor man's RTTI", returns a UClassID for this class.
      *
      * @stable ICU 2.2
      */
     static UClassID U_EXPORT2 getStaticClassID();
 protected:
     // protected method -------------------------------------------------
     /**
      * Search forward for matching text, starting at a given location.
      * Clients should not call this method directly; instead they should
      * call {@link SearchIterator#next }.
      * <p>
      * If a match is found, this method returns the index at which the match
      * starts and calls {@link SearchIterator#setMatchLength } with the number
      * of characters in the target text that make up the match. If no match
      * is found, the method returns <tt>USEARCH_DONE</tt>.
      * <p>
      * The <tt>StringSearch</tt> is adjusted so that its current index
      * (as returned by {@link #getOffset }) is the match position if one was
      * found.
      * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and
      * the <tt>StringSearch</tt> will be adjusted to the index USEARCH_DONE.
      * @param position The index in the target text at which the search
      *                 starts
      * @param status for errors if any occurs
      * @return The index at which the matched text in the target starts, or
      *         USEARCH_DONE if no match was found.
      * @stable ICU 2.0
      */
     virtual int32_t handleNext(int32_t position, UErrorCode &status);
     /**
      * Search backward for matching text, starting at a given location.
      * Clients should not call this method directly; instead they should call
      * <tt>SearchIterator.previous()</tt>, which this method overrides.
      * <p>
      * If a match is found, this method returns the index at which the match
      * starts and calls {@link SearchIterator#setMatchLength } with the number
      * of characters in the target text that make up the match. If no match
      * is found, the method returns <tt>USEARCH_DONE</tt>.
      * <p>
      * The <tt>StringSearch</tt> is adjusted so that its current index
      * (as returned by {@link #getOffset }) is the match position if one was
      * found.
      * If a match is not found, <tt>USEARCH_DONE</tt> will be returned and
      * the <tt>StringSearch</tt> will be adjusted to the index USEARCH_DONE.
      * @param position The index in the target text at which the search
      *                 starts.
      * @param status for errors if any occurs
      * @return The index at which the matched text in the target starts, or
      *         USEARCH_DONE if no match was found.
      * @stable ICU 2.0
      */
     virtual int32_t handlePrev(int32_t position, UErrorCode &status);
 private :
     StringSearch(); // default constructor not implemented
     // private data members ----------------------------------------------
     /**
     * RuleBasedCollator, contains exactly the same UCollator * in m_strsrch_
     * @stable ICU 2.0
     */
     RuleBasedCollator  m_collator_;
     /**
     * Pattern text
     * @stable ICU 2.0
     */
     UnicodeString      m_pattern_;
     /**
     * String search struct data
     * @stable ICU 2.0
     */
     UStringSearch     *m_strsrch_;
 };
 U_NAMESPACE_END
 #endif /* #if !UCONFIG_NO_COLLATION */
 #endif

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intl/icu/source/i18n/unicode/stsearch.h@fc2d59ddac77 (annotated)

intl/icu/source/i18n/unicode/stsearch.h