/*==============================================================================
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Copyright (c) 2001-2011 Joel de Guzman
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Copyright (c) 2010 Bryce Lelbach
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Copyright (c) 2014 Tomoki Imai
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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==============================================================================*/
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#if !defined(BOOST_SPIRIT_SUPPORT_LINE_POS_ITERATOR)
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#define BOOST_SPIRIT_SUPPORT_LINE_POS_ITERATOR
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#include <boost/iterator/iterator_adaptor.hpp>
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#include <boost/range/iterator_range_core.hpp>
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namespace boost { namespace spirit
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{
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//[line_pos_iterator_class
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/*`The `line_pos_iterator` is a lightweight line position iterator.
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This iterator adapter only stores the current line number, nothing else.
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Unlike __classic__'s `position_iterator`, it does not store the
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column number and does not need an end iterator. The current column can
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be computed, if needed. */
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//`[heading Class Reference]
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template <class Iterator>
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class line_pos_iterator : public boost::iterator_adaptor<
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line_pos_iterator<Iterator> // Derived
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, Iterator // Base
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, boost::use_default // Value
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, boost::forward_traversal_tag // CategoryOrTraversal
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> {
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public:
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line_pos_iterator();
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explicit line_pos_iterator(Iterator);
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std::size_t position() const;
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private:
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friend class boost::iterator_core_access;
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void increment();
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std::size_t line; // The line position.
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typename std::iterator_traits<Iterator>::value_type prev;
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};
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//]
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template <class Iterator>
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line_pos_iterator<Iterator>::line_pos_iterator() :
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line_pos_iterator::iterator_adaptor_(), line(1), prev(0) { }
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template <class Iterator>
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line_pos_iterator<Iterator>::line_pos_iterator(Iterator base) :
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line_pos_iterator::iterator_adaptor_(base), line(1), prev(0) { }
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template <class Iterator>
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std::size_t line_pos_iterator<Iterator>::position() const
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{
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return line;
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}
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template<class Iterator>
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void line_pos_iterator<Iterator>::increment()
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{
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typename std::iterator_traits<Iterator>::reference
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ref = *(this->base());
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switch (ref) {
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case '\r':
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if (prev != '\n')
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++line;
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break;
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case '\n':
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if (prev != '\r')
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++line;
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break;
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default:
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break;
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}
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prev = ref;
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++this->base_reference();
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}
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//[line_pos_iterator_utilities
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//`[heading get_line]
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template <class Iterator>
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inline std::size_t get_line(Iterator);
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/*`Get the line position. Returns -1 if Iterator is not a
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`line_pos_iterator`. */
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//`[heading get_line_start]
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template <class Iterator>
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inline Iterator get_line_start(Iterator lower_bound, Iterator current);
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/*`Get an iterator to the beginning of the line. Applicable to any
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iterator. */
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//`[heading get_current_line]
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template <class Iterator>
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inline iterator_range<Iterator>
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get_current_line(Iterator lower_bound, Iterator current,
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Iterator upper_bound);
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/*`Get an `iterator_range` containing the current line. Applicable to any
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iterator. */
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//`[heading get_column]
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template <class Iterator>
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inline std::size_t get_column(Iterator lower_bound, Iterator current,
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std::size_t tabs = 4);
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/*`Get the current column. Applicable to any iterator. */
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//]
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template <class Iterator>
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inline std::size_t get_line(Iterator)
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{
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return -1;
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}
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template <class Iterator>
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inline std::size_t get_line(line_pos_iterator<Iterator> i)
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{
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return i.position();
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}
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template <class Iterator>
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inline Iterator get_line_start(Iterator lower_bound, Iterator current)
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{
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Iterator latest = lower_bound;
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bool prev_was_newline = false;
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for (Iterator i = lower_bound; i != current; ++i) {
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if (prev_was_newline) {
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latest = i;
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}
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prev_was_newline = (*i == '\r') || (*i == '\n');
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}
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if (prev_was_newline) {
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latest = current;
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}
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return latest;
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}
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template <class Iterator>
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inline Iterator get_line_end(Iterator current, Iterator upper_bound)
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{
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for (Iterator i = current; i != upper_bound; ++i) {
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if ((*i == '\n') || (*i == '\r')) {
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return i;
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}
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}
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return upper_bound;
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}
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template <class Iterator>
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inline iterator_range<Iterator>
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get_current_line(Iterator lower_bound,
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Iterator current,
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Iterator upper_bound)
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{
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Iterator first = get_line_start(lower_bound, current);
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Iterator last = get_line_end(current, upper_bound);
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return iterator_range<Iterator>(first, last);
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}
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template <class Iterator>
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inline std::size_t get_column(Iterator lower_bound,
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Iterator current,
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std::size_t tabs)
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{
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std::size_t column = 1;
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Iterator first = get_line_start(lower_bound, current);
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for (Iterator i = first; i != current; ++i) {
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switch (*i) {
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case '\t':
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column += tabs - (column - 1) % tabs;
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break;
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default:
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++column;
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}
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}
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return column;
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}
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}}
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#endif // BOOST_SPIRIT_SUPPORT_LINE_POS_ITERATOR
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