// Copyright (c) 2001-2011 Hartmut Kaiser
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// Copyright (c) 2001-2011 Joel de Guzman
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//
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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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#ifndef BOOST_SPIRIT_KARMA_DIRECTIVE_REPEAT_HPP
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#define BOOST_SPIRIT_KARMA_DIRECTIVE_REPEAT_HPP
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#if defined(_MSC_VER)
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#pragma once
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#endif
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#include <boost/spirit/home/karma/meta_compiler.hpp>
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#include <boost/spirit/home/karma/detail/output_iterator.hpp>
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#include <boost/spirit/home/karma/detail/get_stricttag.hpp>
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#include <boost/spirit/home/karma/generator.hpp>
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#include <boost/spirit/home/karma/auxiliary/lazy.hpp>
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#include <boost/spirit/home/karma/operator/kleene.hpp>
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#include <boost/spirit/home/support/container.hpp>
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#include <boost/spirit/home/support/common_terminals.hpp>
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#include <boost/spirit/home/support/has_semantic_action.hpp>
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#include <boost/spirit/home/support/handles_container.hpp>
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#include <boost/spirit/home/karma/detail/attributes.hpp>
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#include <boost/spirit/home/support/info.hpp>
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#include <boost/fusion/include/at.hpp>
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namespace boost { namespace spirit
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{
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///////////////////////////////////////////////////////////////////////////
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// Enablers
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///////////////////////////////////////////////////////////////////////////
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template <>
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struct use_directive<karma::domain, tag::repeat> // enables repeat[p]
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: mpl::true_ {};
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template <typename T>
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struct use_directive<karma::domain
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, terminal_ex<tag::repeat // enables repeat(exact)[p]
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, fusion::vector1<T> >
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> : mpl::true_ {};
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template <typename T>
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struct use_directive<karma::domain
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, terminal_ex<tag::repeat // enables repeat(min, max)[p]
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, fusion::vector2<T, T> >
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> : mpl::true_ {};
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template <typename T>
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struct use_directive<karma::domain
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, terminal_ex<tag::repeat // enables repeat(min, inf)[p]
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, fusion::vector2<T, inf_type> >
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> : mpl::true_ {};
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template <> // enables *lazy* repeat(exact)[p]
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struct use_lazy_directive<
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karma::domain
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, tag::repeat
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, 1 // arity
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> : mpl::true_ {};
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template <> // enables *lazy* repeat(min, max)[p]
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struct use_lazy_directive< // and repeat(min, inf)[p]
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karma::domain
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, tag::repeat
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, 2 // arity
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> : mpl::true_ {};
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}}
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namespace boost { namespace spirit { namespace karma
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{
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#ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
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using spirit::repeat;
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using spirit::inf;
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#endif
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using spirit::repeat_type;
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using spirit::inf_type;
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///////////////////////////////////////////////////////////////////////////
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// handles repeat(exact)[p]
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template <typename T>
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struct exact_iterator
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{
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exact_iterator(T const exact)
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: exact(exact) {}
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typedef T type;
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T start() const { return 0; }
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bool got_max(T i) const { return i >= exact; }
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bool got_min(T i) const { return i >= exact; }
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T const exact;
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// silence MSVC warning C4512: assignment operator could not be generated
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BOOST_DELETED_FUNCTION(exact_iterator& operator= (exact_iterator const&))
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};
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// handles repeat(min, max)[p]
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template <typename T>
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struct finite_iterator
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{
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finite_iterator(T const min, T const max)
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: min BOOST_PREVENT_MACRO_SUBSTITUTION (min)
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, max BOOST_PREVENT_MACRO_SUBSTITUTION (max) {}
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typedef T type;
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T start() const { return 0; }
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bool got_max(T i) const { return i >= max; }
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bool got_min(T i) const { return i >= min; }
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T const min;
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T const max;
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// silence MSVC warning C4512: assignment operator could not be generated
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BOOST_DELETED_FUNCTION(finite_iterator& operator= (finite_iterator const&))
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};
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// handles repeat(min, inf)[p]
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template <typename T>
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struct infinite_iterator
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{
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infinite_iterator(T const min)
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: min BOOST_PREVENT_MACRO_SUBSTITUTION (min) {}
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typedef T type;
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T start() const { return 0; }
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bool got_max(T /*i*/) const { return false; }
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bool got_min(T i) const { return i >= min; }
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T const min;
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// silence MSVC warning C4512: assignment operator could not be generated
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BOOST_DELETED_FUNCTION(infinite_iterator& operator= (infinite_iterator const&))
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};
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///////////////////////////////////////////////////////////////////////////
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template <typename Subject, typename LoopIter, typename Strict
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, typename Derived>
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struct base_repeat_generator : unary_generator<Derived>
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{
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private:
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// iterate over the given container until its exhausted or the embedded
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// generator succeeds
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template <typename F, typename Attribute>
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bool generate_subject(F f, Attribute const&, mpl::false_) const
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{
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// Failing subject generators are just skipped. This allows to
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// selectively generate items in the provided attribute.
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while (!f.is_at_end())
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{
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bool r = !f(subject);
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if (r)
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return true;
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if (!f.is_at_end())
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f.next();
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}
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return false;
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}
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template <typename F, typename Attribute>
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bool generate_subject(F f, Attribute const&, mpl::true_) const
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{
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return !f(subject);
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}
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// There is no way to distinguish a failed generator from a
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// generator to be skipped. We assume the user takes responsibility
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// for ending the loop if no attribute is specified.
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template <typename F>
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bool generate_subject(F f, unused_type, mpl::false_) const
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{
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return !f(subject);
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}
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public:
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typedef Subject subject_type;
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typedef mpl::int_<subject_type::properties::value> properties;
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// Build a std::vector from the subject's attribute. Note
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// that build_std_vector may return unused_type if the
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// subject's attribute is an unused_type.
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template <typename Context, typename Iterator>
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struct attribute
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: traits::build_std_vector<
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typename traits::attribute_of<Subject, Context, Iterator>::type
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>
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{};
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base_repeat_generator(Subject const& subject, LoopIter const& iter)
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: subject(subject), iter(iter) {}
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template <typename OutputIterator, typename Context, typename Delimiter
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, typename Attribute>
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bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
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, Attribute const& attr) const
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{
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typedef detail::fail_function<
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OutputIterator, Context, Delimiter
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> fail_function;
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typedef typename traits::container_iterator<
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typename add_const<Attribute>::type
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>::type iterator_type;
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typedef
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typename traits::make_indirect_iterator<iterator_type>::type
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indirect_iterator_type;
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typedef detail::pass_container<
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fail_function, Attribute, indirect_iterator_type, mpl::false_>
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pass_container;
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iterator_type it = traits::begin(attr);
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iterator_type end = traits::end(attr);
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pass_container pass(fail_function(sink, ctx, d),
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indirect_iterator_type(it), indirect_iterator_type(end));
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// generate the minimal required amount of output
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typename LoopIter::type i = iter.start();
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for (/**/; !pass.is_at_end() && !iter.got_min(i); ++i)
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{
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if (!generate_subject(pass, attr, Strict()))
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{
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// if we fail before reaching the minimum iteration
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// required, do not output anything and return false
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return false;
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}
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}
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if (pass.is_at_end() && !iter.got_min(i))
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return false; // insufficient attribute elements
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// generate some more up to the maximum specified
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for (/**/; !pass.is_at_end() && !iter.got_max(i); ++i)
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{
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if (!generate_subject(pass, attr, Strict()))
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break;
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}
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return detail::sink_is_good(sink);
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}
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template <typename Context>
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info what(Context& context) const
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{
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return info("repeat", subject.what(context));
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}
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Subject subject;
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LoopIter iter;
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};
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template <typename Subject, typename LoopIter>
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struct repeat_generator
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: base_repeat_generator<
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Subject, LoopIter, mpl::false_
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, repeat_generator<Subject, LoopIter> >
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{
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typedef base_repeat_generator<
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Subject, LoopIter, mpl::false_, repeat_generator
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> base_repeat_generator_;
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repeat_generator(Subject const& subject, LoopIter const& iter)
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: base_repeat_generator_(subject, iter) {}
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};
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template <typename Subject, typename LoopIter>
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struct strict_repeat_generator
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: base_repeat_generator<
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Subject, LoopIter, mpl::true_
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, strict_repeat_generator<Subject, LoopIter> >
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{
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typedef base_repeat_generator<
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Subject, LoopIter, mpl::true_, strict_repeat_generator
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> base_repeat_generator_;
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strict_repeat_generator(Subject const& subject, LoopIter const& iter)
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: base_repeat_generator_(subject, iter) {}
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};
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///////////////////////////////////////////////////////////////////////////
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// Generator generators: make_xxx function (objects)
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///////////////////////////////////////////////////////////////////////////
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template <typename Subject, typename Modifiers>
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struct make_directive<tag::repeat, Subject, Modifiers>
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{
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typedef typename mpl::if_<
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detail::get_stricttag<Modifiers>
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, strict_kleene<Subject>, kleene<Subject>
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>::type result_type;
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result_type operator()(unused_type, Subject const& subject
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, unused_type) const
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{
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return result_type(subject);
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}
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};
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template <typename T, typename Subject, typename Modifiers>
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struct make_directive<
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terminal_ex<tag::repeat, fusion::vector1<T> >, Subject, Modifiers>
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{
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typedef exact_iterator<T> iterator_type;
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typedef typename mpl::if_<
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detail::get_stricttag<Modifiers>
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, strict_repeat_generator<Subject, iterator_type>
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, repeat_generator<Subject, iterator_type>
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>::type result_type;
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template <typename Terminal>
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result_type operator()(
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Terminal const& term, Subject const& subject, unused_type) const
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{
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return result_type(subject, fusion::at_c<0>(term.args));
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}
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};
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template <typename T, typename Subject, typename Modifiers>
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struct make_directive<
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terminal_ex<tag::repeat, fusion::vector2<T, T> >, Subject, Modifiers>
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{
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typedef finite_iterator<T> iterator_type;
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typedef typename mpl::if_<
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detail::get_stricttag<Modifiers>
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, strict_repeat_generator<Subject, iterator_type>
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, repeat_generator<Subject, iterator_type>
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>::type result_type;
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template <typename Terminal>
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result_type operator()(
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Terminal const& term, Subject const& subject, unused_type) const
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{
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return result_type(subject,
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iterator_type(
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fusion::at_c<0>(term.args)
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, fusion::at_c<1>(term.args)
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)
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);
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}
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};
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template <typename T, typename Subject, typename Modifiers>
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struct make_directive<
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terminal_ex<tag::repeat
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, fusion::vector2<T, inf_type> >, Subject, Modifiers>
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{
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typedef infinite_iterator<T> iterator_type;
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typedef typename mpl::if_<
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detail::get_stricttag<Modifiers>
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, strict_repeat_generator<Subject, iterator_type>
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, repeat_generator<Subject, iterator_type>
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>::type result_type;
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template <typename Terminal>
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result_type operator()(
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Terminal const& term, Subject const& subject, unused_type) const
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{
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return result_type(subject, fusion::at_c<0>(term.args));
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}
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};
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}}}
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namespace boost { namespace spirit { namespace traits
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{
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///////////////////////////////////////////////////////////////////////////
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template <typename Subject, typename LoopIter>
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struct has_semantic_action<karma::repeat_generator<Subject, LoopIter> >
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: unary_has_semantic_action<Subject> {};
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template <typename Subject, typename LoopIter>
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struct has_semantic_action<karma::strict_repeat_generator<Subject, LoopIter> >
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: unary_has_semantic_action<Subject> {};
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///////////////////////////////////////////////////////////////////////////
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template <typename Subject, typename LoopIter, typename Attribute
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, typename Context, typename Iterator>
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struct handles_container<
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karma::repeat_generator<Subject, LoopIter>, Attribute
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, Context, Iterator>
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: mpl::true_ {};
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template <typename Subject, typename LoopIter, typename Attribute
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, typename Context, typename Iterator>
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struct handles_container<
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karma::strict_repeat_generator<Subject, LoopIter>, Attribute
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, Context, Iterator>
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: mpl::true_ {};
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}}}
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#endif
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