boost/spirit/home/qi/numeric/bool.hpp
/*=============================================================================
Copyright (c) 2001-2011 Hartmut Kaiser
Copyright (c) 2011 Bryce Lelbach
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)
==============================================================================*/
#ifndef BOOST_SPIRIT_QI_NUMERIC_BOOL_HPP
#define BOOST_SPIRIT_QI_NUMERIC_BOOL_HPP
#if defined(_MSC_VER)
#pragma once
#endif
#include <boost/spirit/home/qi/skip_over.hpp>
#include <boost/spirit/home/qi/detail/enable_lit.hpp>
#include <boost/spirit/home/qi/meta_compiler.hpp>
#include <boost/spirit/home/qi/parser.hpp>
#include <boost/spirit/home/qi/numeric/bool_policies.hpp>
#include <boost/spirit/home/support/common_terminals.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/type_traits/is_same.hpp>
namespace boost { namespace spirit
{
namespace qi
{
///////////////////////////////////////////////////////////////////////
// forward declaration only
template <typename T>
struct bool_policies;
///////////////////////////////////////////////////////////////////////
// This is the class that the user can instantiate directly in
// order to create a customized bool parser
template <typename T, typename BoolPolicies = bool_policies<T> >
struct bool_parser
: spirit::terminal<tag::stateful_tag<BoolPolicies, tag::bool_, T> >
{
typedef tag::stateful_tag<BoolPolicies, tag::bool_, T> tag_type;
bool_parser() {}
bool_parser(BoolPolicies const& data)
: spirit::terminal<tag_type>(data) {}
};
}
///////////////////////////////////////////////////////////////////////////
// Enablers
///////////////////////////////////////////////////////////////////////////
template <> // enables bool_
struct use_terminal<qi::domain, tag::bool_>
: mpl::true_ {};
template <> // enables true_
struct use_terminal<qi::domain, tag::true_>
: mpl::true_ {};
template <> // enables false_
struct use_terminal<qi::domain, tag::false_>
: mpl::true_ {};
///////////////////////////////////////////////////////////////////////////
template <typename A0> // enables lit(...)
struct use_terminal<qi::domain
, terminal_ex<tag::lit, fusion::vector1<A0> >
, typename enable_if<is_same<A0, bool> >::type>
: mpl::true_ {};
///////////////////////////////////////////////////////////////////////////
template <typename A0> // enables bool_(...)
struct use_terminal<qi::domain
, terminal_ex<tag::bool_, fusion::vector1<A0> >
> : mpl::true_ {};
template <> // enables *lazy* bool_(...)
struct use_lazy_terminal<qi::domain, tag::bool_, 1>
: mpl::true_ {};
///////////////////////////////////////////////////////////////////////////
// enables any custom bool_parser
template <typename T, typename BoolPolicies>
struct use_terminal<qi::domain
, tag::stateful_tag<BoolPolicies, tag::bool_, T> >
: mpl::true_ {};
// enables any custom bool_parser(...)
template <typename T, typename BoolPolicies, typename A0>
struct use_terminal<qi::domain
, terminal_ex<tag::stateful_tag<BoolPolicies, tag::bool_, T>
, fusion::vector1<A0> > >
: mpl::true_ {};
// enables *lazy* custom bool_parser(...)
template <typename T, typename BoolPolicies>
struct use_lazy_terminal<
qi::domain
, tag::stateful_tag<BoolPolicies, tag::bool_, T>
, 1 // arity
> : mpl::true_ {};
}}
namespace boost { namespace spirit { namespace qi
{
#ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
using spirit::bool_;
using spirit::true_;
using spirit::false_;
using spirit::lit; // lit(true) is equivalent to true
#endif
using spirit::bool_type;
using spirit::true_type;
using spirit::false_type;
using spirit::lit_type;
namespace detail
{
template <typename T, typename BoolPolicies>
struct bool_impl
{
template <typename Iterator, typename Attribute>
static bool parse(Iterator& first, Iterator const& last
, Attribute& attr, BoolPolicies const& p, bool allow_true = true
, bool disallow_false = false)
{
if (first == last)
return false;
#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
(void)p; // suppresses warning: C4100: 'p' : unreferenced formal parameter
#endif
return (allow_true && p.parse_true(first, last, attr)) ||
(!disallow_false && p.parse_false(first, last, attr));
}
};
}
///////////////////////////////////////////////////////////////////////////
// This actual boolean parser
///////////////////////////////////////////////////////////////////////////
template <typename T, typename BoolPolicies = bool_policies<T> >
struct any_bool_parser
: primitive_parser<any_bool_parser<T, BoolPolicies> >
{
template <typename Context, typename Iterator>
struct attribute
{
typedef T type;
};
template <typename Iterator, typename Context
, typename Skipper, typename Attribute>
bool parse(Iterator& first, Iterator const& last
, Context& /*context*/, Skipper const& skipper
, Attribute& attr_) const
{
typedef detail::bool_impl<T, BoolPolicies> extract;
qi::skip_over(first, last, skipper);
return extract::parse(first, last, attr_, BoolPolicies());
}
template <typename Context>
info what(Context& /*context*/) const
{
return info("boolean");
}
};
template <typename T, typename BoolPolicies = bool_policies<T>
, bool no_attribute = true>
struct literal_bool_parser
: primitive_parser<literal_bool_parser<T, BoolPolicies, no_attribute> >
{
template <typename Value>
literal_bool_parser(Value const& n) : n_(n) {}
template <typename Context, typename Iterator>
struct attribute
: mpl::if_c<no_attribute, unused_type, T>
{};
template <typename Iterator, typename Context
, typename Skipper, typename Attribute>
bool parse(Iterator& first, Iterator const& last
, Context& /*context*/, Skipper const& skipper
, Attribute& attr_) const
{
typedef detail::bool_impl<T, BoolPolicies> extract;
qi::skip_over(first, last, skipper);
return extract::parse(first, last, attr_, BoolPolicies(), n_, n_);
}
template <typename Context>
info what(Context& /*context*/) const
{
return info("boolean");
}
T n_;
};
///////////////////////////////////////////////////////////////////////////
// Parser generators: make_xxx function (objects)
///////////////////////////////////////////////////////////////////////////
template <typename T, typename Modifiers
, typename Policies = bool_policies<T> >
struct make_bool
{
typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
no_case;
typedef typename mpl::if_<
mpl::and_<
no_case
, is_same<bool_policies<T>, Policies>
>
, any_bool_parser<T, no_case_bool_policies<T> >
, any_bool_parser<T, Policies> >::type
result_type;
result_type operator()(unused_type, unused_type) const
{
return result_type();
}
};
template <typename T, typename Modifiers
, typename Policies = bool_policies<T> >
struct make_direct_bool
{
typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
no_case;
typedef typename mpl::if_<
mpl::and_<
no_case
, is_same<bool_policies<T>, Policies>
>
, literal_bool_parser<T, no_case_bool_policies<T>, false>
, literal_bool_parser<T, Policies, false> >::type
result_type;
template <typename Terminal>
result_type operator()(Terminal const& term, unused_type) const
{
return result_type(fusion::at_c<0>(term.args));
}
};
template <typename T, typename Modifiers, bool b
, typename Policies = bool_policies<T> >
struct make_predefined_direct_bool
{
typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
no_case;
typedef typename mpl::if_<
mpl::and_<
no_case
, is_same<bool_policies<T>, Policies>
>
, literal_bool_parser<T, no_case_bool_policies<T>, false>
, literal_bool_parser<T, Policies, false> >::type
result_type;
result_type operator()(unused_type, unused_type) const
{
return result_type(b);
}
};
template <typename T, typename Modifiers
, typename Policies = bool_policies<T> >
struct make_literal_bool
{
typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
no_case;
typedef typename mpl::if_<
mpl::and_<
no_case
, is_same<bool_policies<T>, Policies>
>
, literal_bool_parser<T, no_case_bool_policies<T> >
, literal_bool_parser<T, Policies> >::type
result_type;
template <typename Terminal>
result_type operator()(Terminal const& term, unused_type) const
{
return result_type(fusion::at_c<0>(term.args));
}
};
///////////////////////////////////////////////////////////////////////////
template <typename Modifiers, typename A0>
struct make_primitive<
terminal_ex<tag::lit, fusion::vector1<A0> >
, Modifiers, typename enable_if<is_same<A0, bool> >::type>
: make_literal_bool<bool, Modifiers> {};
///////////////////////////////////////////////////////////////////////////
template <typename Modifiers>
struct make_primitive<tag::false_, Modifiers>
: make_predefined_direct_bool<bool, Modifiers, false>
{};
template <typename Modifiers>
struct make_primitive<tag::true_, Modifiers>
: make_predefined_direct_bool<bool, Modifiers, true>
{};
///////////////////////////////////////////////////////////////////////////
template <typename T, typename Policies, typename Modifiers>
struct make_primitive<
tag::stateful_tag<Policies, tag::bool_, T>, Modifiers>
: make_bool<T, Modifiers, Policies> {};
template <typename T, typename Policies, typename A0, typename Modifiers>
struct make_primitive<
terminal_ex<tag::stateful_tag<Policies, tag::bool_, T>
, fusion::vector1<A0> >, Modifiers>
: make_direct_bool<T, Modifiers, Policies> {};
///////////////////////////////////////////////////////////////////////////
template <typename Modifiers>
struct make_primitive<tag::bool_, Modifiers>
: make_bool<bool, Modifiers> {};
template <typename Modifiers, typename A0>
struct make_primitive<
terminal_ex<tag::bool_
, fusion::vector1<A0> >, Modifiers>
: make_direct_bool<bool, Modifiers> {};
}}}
#endif
