boost/spirit/iterator/position_iterator.hpp
/*=============================================================================
Copyright (c) 2002 Juan Carlos Arevalo-Baeza
Copyright (c) 2002-2003 Hartmut Kaiser
Copyright (c) 2003 Giovanni Bajo
http://spirit.sourceforge.net/
Use, modification and distribution is subject to the Boost Software
License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef BOOST_SPIRIT_POSITION_ITERATOR_HPP
#define BOOST_SPIRIT_POSITION_ITERATOR_HPP
#include <string>
#include <boost/config.hpp>
#include <boost/concept_check.hpp>
namespace boost { namespace spirit {
///////////////////////////////////////////////////////////////////////////////
//
// file_position_without_column
//
// A structure to hold positional information. This includes the file,
// and the line number
//
///////////////////////////////////////////////////////////////////////////////
struct file_position_without_column {
std::string file;
int line;
file_position_without_column(std::string const& file_ = std::string(),
int line_ = 1):
file (file_),
line (line_)
{}
bool operator==(const file_position_without_column& fp) const
{ return line == fp.line && file == fp.file; }
};
///////////////////////////////////////////////////////////////////////////////
//
// file_position
//
// This structure holds complete file position, including file name,
// line and column number
//
///////////////////////////////////////////////////////////////////////////////
struct file_position : public file_position_without_column {
int column;
file_position(std::string const& file_ = std::string(),
int line_ = 1, int column_ = 1):
file_position_without_column (file_, line_),
column (column_)
{}
bool operator==(const file_position& fp) const
{ return column == fp.column && line == fp.line && file == fp.file; }
};
///////////////////////////////////////////////////////////////////////////////
//
// position_policy<>
//
// This template is the policy to handle the file position. It is specialized
// on the position type. Providing a custom file_position also requires
// providing a specialization of this class.
//
// Policy interface:
//
// Default constructor of the custom position class must be accessible.
// set_tab_chars(unsigned int chars) - Set the tabstop width
// next_char(PositionT& pos) - Notify that a new character has been
// processed
// tabulation(PositionT& pos) - Notify that a tab character has been
// processed
// next_line(PositionT& pos) - Notify that a new line delimiter has
// been reached.
//
///////////////////////////////////////////////////////////////////////////////
template <typename PositionT>
class position_policy;
// Forward declaration
template <typename ForwardIteratorT, typename PositionT, typename SelfT>
class position_iterator;
///////////////////////////////////////////////////////////////////////////////
}} /* namespace boost::spirit */
// This must be included here for full compatibility with old MSVC
#include "boost/spirit/iterator/impl/position_iterator.ipp"
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {
///////////////////////////////////////////////////////////////////////////////
//
// position_iterator
//
// It wraps an iterator, and keeps track of the current position in the input,
// as it gets incremented.
//
// The wrapped iterator must be at least a Forward iterator. The position
// iterator itself will always be a non-mutable Forward iterator.
//
// In order to have begin/end iterators constructed, the end iterator must be
// empty constructed. Similar to what happens with stream iterators. The begin
// iterator must be constructed from both, the begin and end iterators of the
// wrapped iterator type. This is necessary to implement the lookahead of
// characters necessary to parse CRLF sequences.
//
// In order to extract the current positional data from the iterator, you may
// use the get_position member function.
//
// You can also use the set_position member function to reset the current
// position to something new.
//
// The structure that holds the current position can be customized through a
// template parameter, and the class position_policy must be specialized
// on the new type to define how to handle it. Currently, it's possible
// to choose between the file_position and file_position_without_column
// (which saves some overhead if managing current column is not required).
//
///////////////////////////////////////////////////////////////////////////////
#if !defined(BOOST_ITERATOR_ADAPTORS_VERSION) || \
BOOST_ITERATOR_ADAPTORS_VERSION < 0x0200
#error "Please use at least Boost V1.31.0 while compiling the position_iterator class!"
#else // BOOST_ITERATOR_ADAPTORS_VERSION < 0x0200
///////////////////////////////////////////////////////////////////////////////
//
// Uses the newer iterator_adaptor version (should be released with
// Boost V1.31.0)
//
///////////////////////////////////////////////////////////////////////////////
template <
typename ForwardIteratorT,
typename PositionT = file_position,
typename SelfT = nil_t
>
class position_iterator
: public iterator_::impl::position_iterator_base_generator<
SelfT,
ForwardIteratorT,
PositionT
>::type,
public position_policy<PositionT>
{
private:
typedef position_policy<PositionT> position_policy_t;
typedef typename iterator_::impl::position_iterator_base_generator<
SelfT,
ForwardIteratorT,
PositionT
>::type base_t;
typedef typename iterator_::impl::position_iterator_base_generator<
SelfT,
ForwardIteratorT,
PositionT
>::main_iter_t main_iter_t;
public:
typedef PositionT position_t;
position_iterator()
: _isend(true)
{}
position_iterator(
const ForwardIteratorT& begin,
const ForwardIteratorT& end)
: base_t(begin), _end(end), _pos(PositionT()), _isend(begin == end)
{}
template <typename FileNameT>
position_iterator(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
FileNameT fileName)
: base_t(begin), _end(end), _pos(PositionT(fileName)),
_isend(begin == end)
{}
template <typename FileNameT, typename LineT>
position_iterator(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
FileNameT fileName, LineT line)
: base_t(begin), _end(end), _pos(PositionT(fileName, line)),
_isend(begin == end)
{}
template <typename FileNameT, typename LineT, typename ColumnT>
position_iterator(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
FileNameT fileName, LineT line, ColumnT column)
: base_t(begin), _end(end), _pos(PositionT(fileName, line, column)),
_isend(begin == end)
{}
position_iterator(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
const PositionT& pos)
: base_t(begin), _end(end), _pos(pos), _isend(begin == end)
{}
position_iterator(const position_iterator& iter)
: base_t(iter.base()), position_policy_t(iter),
_end(iter._end), _pos(iter._pos), _isend(iter._isend)
{}
position_iterator& operator=(const position_iterator& iter)
{
base_t::operator=(iter);
position_policy_t::operator=(iter);
_end = iter._end;
_pos = iter._pos;
_isend = iter._isend;
return *this;
}
void set_position(PositionT const& newpos) { _pos = newpos; }
PositionT& get_position() { return _pos; }
PositionT const& get_position() const { return _pos; }
void set_tabchars(unsigned int chars)
{
// This function (which comes from the position_policy) has a
// different name on purpose, to avoid messing with using
// declarations or qualified calls to access the base template
// function, which might break some compilers.
this->position_policy_t::set_tab_chars(chars);
}
private:
friend class boost::iterator_core_access;
void increment()
{
typename base_t::reference val = *(this->base());
if (val == '\n' || val == '\r') {
++this->base_reference();
if (this->base_reference() != _end) {
typename base_t::reference val2 = *(this->base());
if ((val == '\n' && val2 == '\r')
|| (val == '\r' && val2 == '\n'))
{
++this->base_reference();
}
}
this->next_line(_pos);
static_cast<main_iter_t &>(*this).newline();
}
else if (val == '\t') {
this->tabulation(_pos);
++this->base_reference();
}
else {
this->next_char(_pos);
++this->base_reference();
}
// The iterator is at the end only if it's the same
// of the
_isend = (this->base_reference() == _end);
}
template <
typename OtherDerivedT, typename OtherIteratorT,
typename V, typename C, typename R, typename D
>
bool equal(iterator_adaptor<OtherDerivedT, OtherIteratorT, V, C, R, D>
const &x) const
{
OtherDerivedT const &rhs = static_cast<OtherDerivedT const &>(x);
bool x_is_end = rhs._isend;
return (_isend && x_is_end) ||
(!_isend && !x_is_end && this->base() == rhs.base());
}
protected:
void newline(void)
{}
ForwardIteratorT _end;
PositionT _pos;
bool _isend;
};
#endif // BOOST_ITERATOR_ADAPTORS_VERSION < 0x0200
///////////////////////////////////////////////////////////////////////////////
//
// position_iterator2
//
// Equivalent to position_iterator, but it is able to extract the current
// line into a string. This is very handy for error reports.
//
// Notice that the footprint of this class is higher than position_iterator,
// (how much depends on how bulky the underlying iterator is), so it should
// be used only if necessary.
//
///////////////////////////////////////////////////////////////////////////////
template
<
typename ForwardIteratorT,
typename PositionT = file_position
>
class position_iterator2
: public position_iterator
<
ForwardIteratorT,
PositionT,
position_iterator2<ForwardIteratorT, PositionT>
>
{
typedef position_iterator
<
ForwardIteratorT,
PositionT,
position_iterator2<ForwardIteratorT, PositionT> // JDG 4-15-03
> base_t;
public:
typedef typename base_t::value_type value_type;
typedef PositionT position_t;
position_iterator2()
{}
position_iterator2(
const ForwardIteratorT& begin,
const ForwardIteratorT& end):
base_t(begin, end),
_startline(begin)
{}
template <typename FileNameT>
position_iterator2(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
FileNameT file):
base_t(begin, end, file),
_startline(begin)
{}
template <typename FileNameT, typename LineT>
position_iterator2(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
FileNameT file, LineT line):
base_t(begin, end, file, line),
_startline(begin)
{}
template <typename FileNameT, typename LineT, typename ColumnT>
position_iterator2(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
FileNameT file, LineT line, ColumnT column):
base_t(begin, end, file, line, column),
_startline(begin)
{}
position_iterator2(
const ForwardIteratorT& begin,
const ForwardIteratorT& end,
const PositionT& pos):
base_t(begin, end, pos),
_startline(begin)
{}
position_iterator2(const position_iterator2& iter)
: base_t(iter), _startline(iter._startline)
{}
position_iterator2& operator=(const position_iterator2& iter)
{
base_t::operator=(iter);
_startline = iter._startline;
return *this;
}
ForwardIteratorT get_currentline_begin(void) const
{ return _startline; }
ForwardIteratorT get_currentline_end(void) const
{ return get_endline(); }
std::basic_string<value_type> get_currentline(void) const
{
return std::basic_string<value_type>
(get_currentline_begin(), get_currentline_end());
}
protected:
ForwardIteratorT _startline;
friend class position_iterator<ForwardIteratorT, PositionT,
position_iterator2<ForwardIteratorT, PositionT> >;
ForwardIteratorT get_endline() const
{
ForwardIteratorT endline = _startline;
while (endline != this->_end && *endline != '\r' && *endline != '\n')
{
++endline;
}
return endline;
}
void newline(void)
{ _startline = this->base(); }
};
}} // namespace boost::spirit
#endif
