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Diffstat (limited to 'intl/icu/source/common/unicode/usetiter.h')
| -rw-r--r-- | intl/icu/source/common/unicode/usetiter.h | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/intl/icu/source/common/unicode/usetiter.h b/intl/icu/source/common/unicode/usetiter.h new file mode 100644 index 0000000000..3168d3b0f6 --- /dev/null +++ b/intl/icu/source/common/unicode/usetiter.h @@ -0,0 +1,323 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +********************************************************************** +* Copyright (c) 2002-2014, International Business Machines +* Corporation and others. All Rights Reserved. +********************************************************************** +*/ +#ifndef USETITER_H +#define USETITER_H + +#include "unicode/utypes.h" + +#if U_SHOW_CPLUSPLUS_API + +#include "unicode/uobject.h" +#include "unicode/unistr.h" + +/** + * \file + * \brief C++ API: UnicodeSetIterator iterates over the contents of a UnicodeSet. + */ + +U_NAMESPACE_BEGIN + +class UnicodeSet; +class UnicodeString; + +/** + * + * UnicodeSetIterator iterates over the contents of a UnicodeSet. It + * iterates over either code points or code point ranges. After all + * code points or ranges have been returned, it returns the + * multicharacter strings of the UnicodeSet, if any. + * + * This class is not intended for public subclassing. + * + * <p>To iterate over code points and strings, use a loop like this: + * <pre> + * UnicodeSetIterator it(set); + * while (it.next()) { + * processItem(it.getString()); + * } + * </pre> + * <p>Each item in the set is accessed as a string. Set elements + * consisting of single code points are returned as strings containing + * just the one code point. + * + * <p>To iterate over code point ranges, instead of individual code points, + * use a loop like this: + * <pre> + * UnicodeSetIterator it(set); + * while (it.nextRange()) { + * if (it.isString()) { + * processString(it.getString()); + * } else { + * processCodepointRange(it.getCodepoint(), it.getCodepointEnd()); + * } + * } + * </pre> + * + * To iterate over only the strings, start with <code>skipToStrings()</code>. + * + * @author M. Davis + * @stable ICU 2.4 + */ +class U_COMMON_API UnicodeSetIterator final : public UObject { + /** + * Value of <tt>codepoint</tt> if the iterator points to a string. + * If <tt>codepoint == IS_STRING</tt>, then examine + * <tt>string</tt> for the current iteration result. + */ + enum { IS_STRING = -1 }; + + /** + * Current code point, or the special value <tt>IS_STRING</tt>, if + * the iterator points to a string. + */ + UChar32 codepoint; + + /** + * When iterating over ranges using <tt>nextRange()</tt>, + * <tt>codepointEnd</tt> contains the inclusive end of the + * iteration range, if <tt>codepoint != IS_STRING</tt>. If + * iterating over code points using <tt>next()</tt>, or if + * <tt>codepoint == IS_STRING</tt>, then the value of + * <tt>codepointEnd</tt> is undefined. + */ + UChar32 codepointEnd; + + /** + * If <tt>codepoint == IS_STRING</tt>, then <tt>string</tt> points + * to the current string. If <tt>codepoint != IS_STRING</tt>, the + * value of <tt>string</tt> is undefined. + */ + const UnicodeString* string; + + public: + + /** + * Create an iterator over the given set. The iterator is valid + * only so long as <tt>set</tt> is valid. + * @param set set to iterate over + * @stable ICU 2.4 + */ + UnicodeSetIterator(const UnicodeSet& set); + + /** + * Create an iterator over nothing. <tt>next()</tt> and + * <tt>nextRange()</tt> return false. This is a convenience + * constructor allowing the target to be set later. + * @stable ICU 2.4 + */ + UnicodeSetIterator(); + + /** + * Destructor. + * @stable ICU 2.4 + */ + virtual ~UnicodeSetIterator(); + + /** + * Returns true if the current element is a string. If so, the + * caller can retrieve it with <tt>getString()</tt>. If this + * method returns false, the current element is a code point or + * code point range, depending on whether <tt>next()</tt> or + * <tt>nextRange()</tt> was called. + * Elements of types string and codepoint can both be retrieved + * with the function <tt>getString()</tt>. + * Elements of type codepoint can also be retrieved with + * <tt>getCodepoint()</tt>. + * For ranges, <tt>getCodepoint()</tt> returns the starting codepoint + * of the range, and <tt>getCodepointEnd()</tt> returns the end + * of the range. + * @stable ICU 2.4 + */ + inline UBool isString() const; + + /** + * Returns the current code point, if <tt>isString()</tt> returned + * false. Otherwise returns an undefined result. + * @stable ICU 2.4 + */ + inline UChar32 getCodepoint() const; + + /** + * Returns the end of the current code point range, if + * <tt>isString()</tt> returned false and <tt>nextRange()</tt> was + * called. Otherwise returns an undefined result. + * @stable ICU 2.4 + */ + inline UChar32 getCodepointEnd() const; + + /** + * Returns the current string, if <tt>isString()</tt> returned + * true. If the current iteration item is a code point, a UnicodeString + * containing that single code point is returned. + * + * Ownership of the returned string remains with the iterator. + * The string is guaranteed to remain valid only until the iterator is + * advanced to the next item, or until the iterator is deleted. + * + * @stable ICU 2.4 + */ + const UnicodeString& getString(); + + /** + * Skips over the remaining code points/ranges, if any. + * A following call to next() or nextRange() will yield a string, if there is one. + * No-op if next() would return false, or if it would yield a string anyway. + * + * @return *this + * @stable ICU 70 + * @see UnicodeSet#strings() + */ + inline UnicodeSetIterator &skipToStrings() { + // Finish code point/range iteration. + range = endRange; + endElement = -1; + nextElement = 0; + return *this; + } + + /** + * Advances the iteration position to the next element in the set, + * which can be either a single code point or a string. + * If there are no more elements in the set, return false. + * + * <p> + * If <tt>isString() == true</tt>, the value is a + * string, otherwise the value is a + * single code point. Elements of either type can be retrieved + * with the function <tt>getString()</tt>, while elements of + * consisting of a single code point can be retrieved with + * <tt>getCodepoint()</tt> + * + * <p>The order of iteration is all code points in sorted order, + * followed by all strings sorted order. Do not mix + * calls to <tt>next()</tt> and <tt>nextRange()</tt> without + * calling <tt>reset()</tt> between them. The results of doing so + * are undefined. + * + * @return true if there was another element in the set. + * @stable ICU 2.4 + */ + UBool next(); + + /** + * Returns the next element in the set, either a code point range + * or a string. If there are no more elements in the set, return + * false. If <tt>isString() == true</tt>, the value is a + * string and can be accessed with <tt>getString()</tt>. Otherwise the value is a + * range of one or more code points from <tt>getCodepoint()</tt> to + * <tt>getCodepointeEnd()</tt> inclusive. + * + * <p>The order of iteration is all code points ranges in sorted + * order, followed by all strings sorted order. Ranges are + * disjoint and non-contiguous. The value returned from <tt>getString()</tt> + * is undefined unless <tt>isString() == true</tt>. Do not mix calls to + * <tt>next()</tt> and <tt>nextRange()</tt> without calling + * <tt>reset()</tt> between them. The results of doing so are + * undefined. + * + * @return true if there was another element in the set. + * @stable ICU 2.4 + */ + UBool nextRange(); + + /** + * Sets this iterator to visit the elements of the given set and + * resets it to the start of that set. The iterator is valid only + * so long as <tt>set</tt> is valid. + * @param set the set to iterate over. + * @stable ICU 2.4 + */ + void reset(const UnicodeSet& set); + + /** + * Resets this iterator to the start of the set. + * @stable ICU 2.4 + */ + void reset(); + + /** + * ICU "poor man's RTTI", returns a UClassID for this class. + * + * @stable ICU 2.4 + */ + static UClassID U_EXPORT2 getStaticClassID(); + + /** + * ICU "poor man's RTTI", returns a UClassID for the actual class. + * + * @stable ICU 2.4 + */ + virtual UClassID getDynamicClassID() const override; + + // ======================= PRIVATES =========================== + +private: + + // endElement and nextElements are really UChar32's, but we keep + // them as signed int32_t's so we can do comparisons with + // endElement set to -1. Leave them as int32_t's. + /** The set + */ + const UnicodeSet* set; + /** End range + */ + int32_t endRange; + /** Range + */ + int32_t range; + /** End element + */ + int32_t endElement; + /** Next element + */ + int32_t nextElement; + /** Next string + */ + int32_t nextString; + /** String count + */ + int32_t stringCount; + + /** + * Points to the string to use when the caller asks for a + * string and the current iteration item is a code point, not a string. + */ + UnicodeString *cpString; + + /** Copy constructor. Disallowed. + */ + UnicodeSetIterator(const UnicodeSetIterator&) = delete; + + /** Assignment operator. Disallowed. + */ + UnicodeSetIterator& operator=(const UnicodeSetIterator&) = delete; + + /** Load range + */ + void loadRange(int32_t range); +}; + +inline UBool UnicodeSetIterator::isString() const { + return codepoint < 0; +} + +inline UChar32 UnicodeSetIterator::getCodepoint() const { + return codepoint; +} + +inline UChar32 UnicodeSetIterator::getCodepointEnd() const { + return codepointEnd; +} + + +U_NAMESPACE_END + +#endif /* U_SHOW_CPLUSPLUS_API */ + +#endif |