ClickHouse/contrib/libpoco/Foundation/include/Poco/TextIterator.h

144 lines
3.4 KiB
C++

//
// TextIterator.h
//
// $Id: //poco/1.4/Foundation/include/Poco/TextIterator.h#1 $
//
// Library: Foundation
// Package: Text
// Module: TextIterator
//
// Definition of the TextIterator class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_TextIterator_INCLUDED
#define Foundation_TextIterator_INCLUDED
#include "Poco/Foundation.h"
namespace Poco {
class TextEncoding;
class Foundation_API TextIterator
/// An unidirectional iterator for iterating over characters in a string.
/// The TextIterator uses a TextEncoding object to
/// work with multi-byte character encodings like UTF-8.
/// Characters are reported in Unicode.
///
/// Example: Count the number of UTF-8 characters in a string.
///
/// UTF8Encoding utf8Encoding;
/// std::string utf8String("....");
/// TextIterator it(utf8String, utf8Encoding);
/// TextIterator end(utf8String);
/// int n = 0;
/// while (it != end) { ++n; ++it; }
///
/// NOTE: When an UTF-16 encoding is used, surrogate pairs will be
/// reported as two separate characters, due to restrictions of
/// the TextEncoding class.
///
/// For iterating over char buffers, see the TextBufferIterator class.
{
public:
TextIterator();
/// Creates an uninitialized TextIterator.
TextIterator(const std::string& str, const TextEncoding& encoding);
/// Creates a TextIterator for the given string.
/// The encoding object must not be deleted as long as the iterator
/// is in use.
TextIterator(const std::string::const_iterator& begin, const std::string::const_iterator& end, const TextEncoding& encoding);
/// Creates a TextIterator for the given range.
/// The encoding object must not be deleted as long as the iterator
/// is in use.
TextIterator(const std::string& str);
/// Creates an end TextIterator for the given string.
TextIterator(const std::string::const_iterator& end);
/// Creates an end TextIterator.
~TextIterator();
/// Destroys the TextIterator.
TextIterator(const TextIterator& it);
/// Copy constructor.
TextIterator& operator = (const TextIterator& it);
/// Assignment operator.
void swap(TextIterator& it);
/// Swaps the iterator with another one.
int operator * () const;
/// Returns the Unicode value of the current character.
/// If there is no valid character at the current position,
/// -1 is returned.
TextIterator& operator ++ ();
/// Prefix increment operator.
TextIterator operator ++ (int);
/// Postfix increment operator.
bool operator == (const TextIterator& it) const;
/// Compares two iterators for equality.
bool operator != (const TextIterator& it) const;
/// Compares two iterators for inequality.
TextIterator end() const;
/// Returns the end iterator for the range handled
/// by the iterator.
private:
const TextEncoding* _pEncoding;
std::string::const_iterator _it;
std::string::const_iterator _end;
};
//
// inlines
//
inline bool TextIterator::operator == (const TextIterator& it) const
{
return _it == it._it;
}
inline bool TextIterator::operator != (const TextIterator& it) const
{
return _it != it._it;
}
inline void swap(TextIterator& it1, TextIterator& it2)
{
it1.swap(it2);
}
inline TextIterator TextIterator::end() const
{
return TextIterator(_end);
}
} // namespace Poco
#endif // Foundation_TextIterator_INCLUDED