Aegisub/libaegisub/include/libaegisub/line_iterator.h
2015-07-30 19:20:10 -07:00

139 lines
4.4 KiB
C++

// Copyright (c) 2010, Thomas Goyne <plorkyeran@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
/// @file line_iterator.h
/// @brief An iterator over lines in a stream
/// @ingroup libaegisub
#pragma once
#include <iterator>
#include <memory>
#include <cstdint>
#include <boost/interprocess/streams/bufferstream.hpp>
namespace agi {
namespace charset { class IconvWrapper; }
class line_iterator_base {
std::istream *stream = nullptr; ///< Stream to iterate over
std::shared_ptr<agi::charset::IconvWrapper> conv;
int cr = '\r'; ///< CR character in the source encoding
int lf = '\n'; ///< LF character in the source encoding
size_t width = 1; ///< width of LF character in the source encoding
protected:
bool getline(std::string &str);
public:
line_iterator_base(std::istream &stream, std::string encoding = "utf-8");
line_iterator_base() = default;
line_iterator_base(line_iterator_base const&) = default;
line_iterator_base(line_iterator_base&&) = default;
line_iterator_base& operator=(line_iterator_base const&) = default;
line_iterator_base& operator=(line_iterator_base&&) = default;
bool operator==(line_iterator_base const& rgt) const { return stream == rgt.stream; }
bool operator!=(line_iterator_base const& rgt) const { return !operator==(rgt); }
};
/// @class line_iterator
/// @brief An iterator over lines in a stream
template<class OutputType = std::string>
class line_iterator final : public line_iterator_base, public std::iterator<std::input_iterator_tag, OutputType> {
OutputType value; ///< Value to return when this is dereference
/// @brief Convert a string to the output type
/// @param str Line read from the file
///
/// line_iterator users can either ensure that operator>> is defined for
/// their desired output type or simply provide a specialization of this
/// method which does the conversion.
inline bool convert(std::string &str);
/// @brief Get the next value from the stream
void next();
public:
/// @brief Constructor
/// @param stream The stream to read from. The calling code is responsible
/// for ensuring that the stream remains valid for the
/// lifetime of the iterator and that it get cleaned up.
/// @param encoding Encoding of the text read from the stream
line_iterator(std::istream &stream, std::string encoding = "utf-8")
: line_iterator_base(stream, std::move(encoding))
{
++(*this);
}
/// @brief Invalid iterator constructor; use for end iterator
line_iterator() = default;
/// @brief Copy constructor
/// @param that line_iterator to copy from
line_iterator(line_iterator<OutputType> const&) = default;
OutputType const& operator*() const { return value; }
OutputType const* operator->() const { return &value; }
line_iterator<OutputType>& operator++() {
next();
return *this;
}
line_iterator<OutputType> operator++(int) {
line_iterator<OutputType> tmp(*this);
++*this;
return tmp;
}
// typedefs needed by some stl algorithms
typedef OutputType* pointer;
typedef OutputType& reference;
typedef const OutputType* const_pointer;
typedef const OutputType& const_reference;
};
// Enable range-based for
template<typename T>
line_iterator<T>& begin(line_iterator<T>& it) { return it; }
template<typename T>
line_iterator<T> end(line_iterator<T>&) { return agi::line_iterator<T>(); }
template<class OutputType>
void line_iterator<OutputType>::next() {
std::string str;
if (!getline(str))
return;
if (!convert(str))
next();
}
template<>
inline void line_iterator<std::string>::next() {
value.clear();
getline(value);
}
template<class OutputType>
inline bool line_iterator<OutputType>::convert(std::string &str) {
boost::interprocess::ibufferstream ss(str.data(), str.size());
ss >> value;
return !ss.fail();
}
}