/*=============================================================================
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Copyright (c) 2014 Joel de Guzman
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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_X3_POSITION_TAGGED_MAY_01_2014_0321PM)
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#define BOOST_SPIRIT_X3_POSITION_TAGGED_MAY_01_2014_0321PM
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#include <boost/range/iterator_range_core.hpp>
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#include <boost/type_traits/is_base_of.hpp>
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#include <boost/core/enable_if.hpp>
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namespace boost { namespace spirit { namespace x3
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{
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struct position_tagged
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{
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// Use this to annotate an AST with the iterator position.
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// These ids are used as a key to the position_cache (below)
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// and marks the start and end of an AST node.
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int id_first = -1;
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int id_last = -1;
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};
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template <typename Container>
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class position_cache
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{
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public:
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typedef typename Container::value_type iterator_type;
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position_cache(
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iterator_type first
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, iterator_type last)
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: first_(first), last_(last) {}
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// This will catch all nodes inheriting from position_tagged
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boost::iterator_range<iterator_type>
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position_of(position_tagged const& ast) const
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{
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return
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boost::iterator_range<iterator_type>(
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positions.at(ast.id_first) // throws if out of range
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, positions.at(ast.id_last) // throws if out of range
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);
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}
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// This will catch all nodes except those inheriting from position_tagged
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template <typename AST>
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typename boost::enable_if_c<
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(!is_base_of<position_tagged, AST>::value)
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, boost::iterator_range<iterator_type>
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>::type
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position_of(AST const& /* ast */) const
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{
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// returns an empty position
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return boost::iterator_range<iterator_type>();
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}
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// This will catch all nodes except those inheriting from position_tagged
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template <typename AST>
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void annotate(AST& /* ast */, iterator_type /* first */, iterator_type /* last */, mpl::false_)
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{
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// (no-op) no need for tags
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}
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// This will catch all nodes inheriting from position_tagged
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void annotate(position_tagged& ast, iterator_type first, iterator_type last, mpl::true_)
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{
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ast.id_first = int(positions.size());
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positions.push_back(first);
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ast.id_last = int(positions.size());
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positions.push_back(last);
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}
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template <typename AST>
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void annotate(AST& ast, iterator_type first, iterator_type last)
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{
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annotate(ast, first, last, is_base_of<position_tagged, AST>());
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}
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Container const&
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get_positions() const
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{
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return positions;
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}
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iterator_type first() const { return first_; }
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iterator_type last() const { return last_; }
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private:
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Container positions;
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iterator_type first_;
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iterator_type last_;
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};
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}}}
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#endif
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