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// © 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