/src/contrib/boost/spirit/home/qi/directive/repeat.hpp
http://pythonocc.googlecode.com/ · C++ Header · 327 lines · 254 code · 43 blank · 30 comment · 7 complexity · 5cf9f871db06d197ca7e113f6265e05f MD5 · raw file
- /*=============================================================================
- Copyright (c) 2001-2010 Joel de Guzman
- Distributed under 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)
- =============================================================================*/
- #if !defined(SPIRIT_REPEAT_NOVEMBER_14_2008_1148AM)
- #define SPIRIT_REPEAT_NOVEMBER_14_2008_1148AM
- #if defined(_MSC_VER)
- #pragma once
- #endif
- #include <boost/spirit/home/qi/meta_compiler.hpp>
- #include <boost/spirit/home/qi/parser.hpp>
- #include <boost/spirit/home/qi/auxiliary/lazy.hpp>
- #include <boost/spirit/home/qi/operator/kleene.hpp>
- #include <boost/spirit/home/support/container.hpp>
- #include <boost/spirit/home/support/common_terminals.hpp>
- #include <boost/spirit/home/support/attributes.hpp>
- #include <boost/spirit/home/support/info.hpp>
- #include <boost/fusion/include/at.hpp>
- #include <boost/foreach.hpp>
- #include <vector>
- namespace boost { namespace spirit
- {
- ///////////////////////////////////////////////////////////////////////////
- // Enablers
- ///////////////////////////////////////////////////////////////////////////
- template <>
- struct use_directive<qi::domain, tag::repeat> // enables repeat[p]
- : mpl::true_ {};
- template <typename T>
- struct use_directive<qi::domain
- , terminal_ex<tag::repeat // enables repeat(exact)[p]
- , fusion::vector1<T> >
- > : mpl::true_ {};
- template <typename T>
- struct use_directive<qi::domain
- , terminal_ex<tag::repeat // enables repeat(min, max)[p]
- , fusion::vector2<T, T> >
- > : mpl::true_ {};
- template <typename T>
- struct use_directive<qi::domain
- , terminal_ex<tag::repeat // enables repeat(min, inf)[p]
- , fusion::vector2<T, inf_type> >
- > : mpl::true_ {};
- template <> // enables *lazy* repeat(exact)[p]
- struct use_lazy_directive<
- qi::domain
- , tag::repeat
- , 1 // arity
- > : mpl::true_ {};
- template <> // enables *lazy* repeat(min, max)[p]
- struct use_lazy_directive< // and repeat(min, inf)[p]
- qi::domain
- , tag::repeat
- , 2 // arity
- > : mpl::true_ {};
- }}
- namespace boost { namespace spirit { namespace qi
- {
- using spirit::repeat;
- using spirit::repeat_type;
- using spirit::inf;
- using spirit::inf_type;
- template <typename T>
- struct exact_iterator // handles repeat(exact)[p]
- {
- exact_iterator(T const exact)
- : exact(exact) {}
- typedef T type;
- T start() const { return 0; }
- bool got_max(T i) const { return i >= exact; }
- bool got_min(T i) const { return i >= exact; }
- T const exact;
- private:
- // silence MSVC warning C4512: assignment operator could not be generated
- exact_iterator& operator= (exact_iterator const&);
- };
- template <typename T>
- struct finite_iterator // handles repeat(min, max)[p]
- {
- finite_iterator(T const min, T const max)
- : min BOOST_PREVENT_MACRO_SUBSTITUTION (min)
- , max BOOST_PREVENT_MACRO_SUBSTITUTION (max) {}
- typedef T type;
- T start() const { return 0; }
- bool got_max(T i) const { return i >= max; }
- bool got_min(T i) const { return i >= min; }
- T const min;
- T const max;
- private:
- // silence MSVC warning C4512: assignment operator could not be generated
- finite_iterator& operator= (finite_iterator const&);
- };
- template <typename T>
- struct infinite_iterator // handles repeat(min, inf)[p]
- {
- infinite_iterator(T const min)
- : min BOOST_PREVENT_MACRO_SUBSTITUTION (min) {}
- typedef T type;
- T start() const { return 0; }
- bool got_max(T /*i*/) const { return false; }
- bool got_min(T i) const { return i >= min; }
- T const min;
- private:
- // silence MSVC warning C4512: assignment operator could not be generated
- infinite_iterator& operator= (infinite_iterator const&);
- };
- template <typename Subject, typename LoopIter>
- struct repeat_parser : unary_parser<repeat_parser<Subject, LoopIter> >
- {
- typedef Subject subject_type;
- template <typename Context, typename Iterator>
- struct attribute
- {
- // Build a std::vector from the subject's attribute. Note
- // that build_std_vector may return unused_type if the
- // subject's attribute is an unused_type.
- typedef typename
- traits::build_std_vector<
- typename traits::attribute_of<
- Subject, Context, Iterator>::type
- >::type
- type;
- };
- repeat_parser(Subject const& subject, LoopIter const& iter)
- : subject(subject), iter(iter) {}
- template <typename Iterator, typename Context
- , typename Skipper, typename ValueType, typename Attribute
- , typename LoopVar>
- bool parse_minimal(Iterator &first, Iterator const& last
- , Context& context, Skipper const& skipper
- , Attribute& attr, ValueType& val, LoopVar& i) const
- {
- // this scope allows save and required_attr to be reclaimed
- // immediately after we're done with the required minimum
- // iteration.
- Iterator save = first;
- std::vector<ValueType> required_attr;
- for (; !iter.got_min(i); ++i)
- {
- if (!subject.parse(save, last, context, skipper, val) ||
- !traits::push_back(required_attr, val))
- {
- return false;
- }
- first = save;
- traits::clear(val);
- }
- // if we got the required number of items, these are copied
- // over (appended) to the 'real' attribute
- BOOST_FOREACH(ValueType const& v, required_attr)
- {
- traits::push_back(attr, v);
- }
- return true;
- }
- template <typename Iterator, typename Context
- , typename Skipper, typename LoopVar>
- bool parse_minimal(Iterator &first, Iterator const& last
- , Context& context, Skipper const& skipper
- , unused_type, unused_type, LoopVar& i) const
- {
- // this scope allows save and required_attr to be reclaimed
- // immediately after we're done with the required minimum
- // iteration.
- Iterator save = first;
- for (; !iter.got_min(i); ++i)
- {
- if (!subject.parse(save, last, context, skipper, unused))
- {
- return false;
- }
- first = save;
- }
- return true;
- }
- template <typename Iterator, typename Context
- , typename Skipper, typename Attribute>
- bool parse(Iterator& first, Iterator const& last
- , Context& context, Skipper const& skipper
- , Attribute& attr) const
- {
- // create a local value if Attribute is not unused_type
- typedef typename traits::container_value<Attribute>::type
- value_type;
- value_type val = value_type();
- typename LoopIter::type i = iter.start();
- // parse the minimum required
- if (!iter.got_min(i) &&
- !parse_minimal(first, last, context, skipper, attr, val, i))
- {
- return false;
- }
- // parse some more up to the maximum specified
- Iterator save = first;
- for (; !iter.got_max(i); ++i)
- {
- if (!subject.parse(save, last, context, skipper, val) ||
- !traits::push_back(attr, val))
- {
- break;
- }
- first = save;
- traits::clear(val);
- }
- return true;
- }
- template <typename Context>
- info what(Context& context) const
- {
- return info("repeat", subject.what(context));
- }
- Subject subject;
- LoopIter iter;
- private:
- // silence MSVC warning C4512: assignment operator could not be generated
- repeat_parser& operator= (repeat_parser const&);
- };
- ///////////////////////////////////////////////////////////////////////////
- // Parser generators: make_xxx function (objects)
- ///////////////////////////////////////////////////////////////////////////
- template <typename Subject, typename Modifiers>
- struct make_directive<tag::repeat, Subject, Modifiers>
- {
- typedef kleene<Subject> result_type;
- result_type operator()(unused_type, Subject const& subject, unused_type) const
- {
- return result_type(subject);
- }
- };
- template <typename T, typename Subject, typename Modifiers>
- struct make_directive<
- terminal_ex<tag::repeat, fusion::vector1<T> >, Subject, Modifiers>
- {
- typedef exact_iterator<T> iterator_type;
- typedef repeat_parser<Subject, iterator_type> result_type;
- template <typename Terminal>
- result_type operator()(
- Terminal const& term, Subject const& subject, unused_type) const
- {
- return result_type(subject, fusion::at_c<0>(term.args));
- }
- };
- template <typename T, typename Subject, typename Modifiers>
- struct make_directive<
- terminal_ex<tag::repeat, fusion::vector2<T, T> >, Subject, Modifiers>
- {
- typedef finite_iterator<T> iterator_type;
- typedef repeat_parser<Subject, iterator_type> result_type;
- template <typename Terminal>
- result_type operator()(
- Terminal const& term, Subject const& subject, unused_type) const
- {
- return result_type(subject,
- iterator_type(
- fusion::at_c<0>(term.args)
- , fusion::at_c<1>(term.args)
- )
- );
- }
- };
- template <typename T, typename Subject, typename Modifiers>
- struct make_directive<
- terminal_ex<tag::repeat
- , fusion::vector2<T, inf_type> >, Subject, Modifiers>
- {
- typedef infinite_iterator<T> iterator_type;
- typedef repeat_parser<Subject, iterator_type> result_type;
- template <typename Terminal>
- result_type operator()(
- Terminal const& term, Subject const& subject, unused_type) const
- {
- return result_type(subject, fusion::at_c<0>(term.args));
- }
- };
- }}}
- namespace boost { namespace spirit { namespace traits
- {
- template <typename Subject, typename LoopIter>
- struct has_semantic_action<qi::repeat_parser<Subject, LoopIter> >
- : unary_has_semantic_action<Subject> {};
- }}}
- #endif