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^?_I|+ ? // © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
**********************************************************************
* Copyright (C) 2001-2014 IBM and others. All rights reserved.
**********************************************************************
* Date Name Description
* 03/22/2000 helena Creation.
**********************************************************************
*/
#ifndef STSEARCH_H
#define STSEARCH_H
#include "unicode/utypes.h"
#if U_SHOW_CPLUSPLUS_API
/**
* \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
/**
*
* StringSearch is a SearchIterator 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 ß and SS will be matched
* if case is chosen to be ignored.
* See the
* "ICU Collation Design Document" for more information.
*
* There are 2 match options for selection:
* Let S' be the sub-string of a text string S between the offsets start and
* end [start, end].
*
* A pattern string P matches a text string S at the offsets [start, end]
* if
*
* 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.
*
* Option 2. will be the default.
*
* This search has APIs similar to that of other text iteration mechanisms
* such as the break iterators in BreakIterator. Using these
* APIs, it is easy to scan through text looking for all occurrences of
* a given pattern. This search iterator allows changing of direction by
* calling a reset followed by a next or previous.
* Though a direction change can occur without calling reset 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
*
* SearchIterator provides APIs to specify the starting position
* within the text string to be searched, e.g. setOffset,
* preceding and following. 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:
*
* - The midst of a substring that requires normalization.
*
- 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.
*
- 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.
*
*
* 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 cha