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

148 lines
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C++

//
// TextBufferIterator.h
//
// $Id: //poco/1.4/Foundation/include/Poco/TextBufferIterator.h#1 $
//
// Library: Foundation
// Package: Text
// Module: TextBufferIterator
//
// Definition of the TextBufferIterator class.
//
// Copyright (c) 2010, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_TextBufferIterator_INCLUDED
#define Foundation_TextBufferIterator_INCLUDED
#include "Poco/Foundation.h"
#include <cstdlib>
namespace Poco {
class TextEncoding;
class Foundation_API TextBufferIterator
/// An unidirectional iterator for iterating over characters in a buffer.
/// The TextBufferIterator 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 buffer.
///
/// UTF8Encoding utf8Encoding;
/// char buffer[] = "...";
/// TextBufferIterator it(buffer, utf8Encoding);
/// TextBufferIterator end(it.end());
/// 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 the characters in a std::string, see the
/// TextIterator class.
{
public:
TextBufferIterator();
/// Creates an uninitialized TextBufferIterator.
TextBufferIterator(const char* begin, const TextEncoding& encoding);
/// Creates a TextBufferIterator for the given buffer, which must be 0-terminated.
/// The encoding object must not be deleted as long as the iterator
/// is in use.
TextBufferIterator(const char* begin, std::size_t size, const TextEncoding& encoding);
/// Creates a TextBufferIterator for the given buffer with the given size.
/// The encoding object must not be deleted as long as the iterator
/// is in use.
TextBufferIterator(const char* begin, const char* end, const TextEncoding& encoding);
/// Creates a TextBufferIterator for the given range.
/// The encoding object must not be deleted as long as the iterator
/// is in use.
TextBufferIterator(const char* end);
/// Creates an end TextBufferIterator for the given buffer.
~TextBufferIterator();
/// Destroys the TextBufferIterator.
TextBufferIterator(const TextBufferIterator& it);
/// Copy constructor.
TextBufferIterator& operator = (const TextBufferIterator& it);
/// Assignment operator.
void swap(TextBufferIterator& 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.
TextBufferIterator& operator ++ ();
/// Prefix increment operator.
TextBufferIterator operator ++ (int);
/// Postfix increment operator.
bool operator == (const TextBufferIterator& it) const;
/// Compares two iterators for equality.
bool operator != (const TextBufferIterator& it) const;
/// Compares two iterators for inequality.
TextBufferIterator end() const;
/// Returns the end iterator for the range handled
/// by the iterator.
private:
const TextEncoding* _pEncoding;
const char* _it;
const char* _end;
};
//
// inlines
//
inline bool TextBufferIterator::operator == (const TextBufferIterator& it) const
{
return _it == it._it;
}
inline bool TextBufferIterator::operator != (const TextBufferIterator& it) const
{
return _it != it._it;
}
inline void swap(TextBufferIterator& it1, TextBufferIterator& it2)
{
it1.swap(it2);
}
inline TextBufferIterator TextBufferIterator::end() const
{
return TextBufferIterator(_end);
}
} // namespace Poco
#endif // Foundation_TextBufferIterator_INCLUDED