vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/xpressive/regex_actions.hpp

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///////////////////////////////////////////////////////////////////////////////
/// \file regex_actions.hpp
/// Defines the syntax elements of xpressive's action expressions.
//
// Copyright 2008 Eric Niebler. 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_XPRESSIVE_ACTIONS_HPP_EAN_03_22_2007
#define BOOST_XPRESSIVE_ACTIONS_HPP_EAN_03_22_2007
// MS compatible compilers support #pragma once
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/config.hpp>
#include <boost/preprocessor/punctuation/comma_if.hpp>
#include <boost/ref.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/or.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/noncopyable.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/throw_exception.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/type_traits/decay.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/range/iterator_range.hpp>
#include <boost/xpressive/detail/detail_fwd.hpp>
#include <boost/xpressive/detail/core/state.hpp>
#include <boost/xpressive/detail/core/matcher/attr_matcher.hpp>
#include <boost/xpressive/detail/core/matcher/attr_end_matcher.hpp>
#include <boost/xpressive/detail/core/matcher/attr_begin_matcher.hpp>
#include <boost/xpressive/detail/core/matcher/predicate_matcher.hpp>
#include <boost/xpressive/detail/utility/ignore_unused.hpp>
#include <boost/xpressive/detail/static/type_traits.hpp>
// These are very often needed by client code.
#include <boost/typeof/std/map.hpp>
#include <boost/typeof/std/string.hpp>
// Doxygen can't handle proto :-(
#ifndef BOOST_XPRESSIVE_DOXYGEN_INVOKED
# include <boost/proto/core.hpp>
# include <boost/proto/transform.hpp>
# include <boost/xpressive/detail/core/matcher/action_matcher.hpp>
#endif
#if BOOST_MSVC
#pragma warning(push)
#pragma warning(disable : 4510) // default constructor could not be generated
#pragma warning(disable : 4512) // assignment operator could not be generated
#pragma warning(disable : 4610) // can never be instantiated - user defined constructor required
#endif
namespace boost { namespace xpressive
{
namespace detail
{
template<typename T, typename U>
struct action_arg
{
typedef T type;
typedef typename add_reference<T>::type reference;
reference cast(void *pv) const
{
return *static_cast<typename remove_reference<T>::type *>(pv);
}
};
template<typename T>
struct value_wrapper
: private noncopyable
{
value_wrapper()
: value()
{}
value_wrapper(T const &t)
: value(t)
{}
T value;
};
struct check_tag
{};
struct BindArg
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename MatchResults, typename Expr>
struct result<This(MatchResults, Expr)>
{
typedef Expr type;
};
template<typename MatchResults, typename Expr>
Expr const & operator ()(MatchResults &what, Expr const &expr) const
{
what.let(expr);
return expr;
}
};
struct let_tag
{};
// let(_a = b, _c = d)
struct BindArgs
: proto::function<
proto::terminal<let_tag>
, proto::vararg<
proto::when<
proto::assign<proto::_, proto::_>
, proto::call<BindArg(proto::_data, proto::_)>
>
>
>
{};
struct let_domain
: boost::proto::domain<boost::proto::pod_generator<let_> >
{};
template<typename Expr>
struct let_
{
BOOST_PROTO_BASIC_EXTENDS(Expr, let_<Expr>, let_domain)
BOOST_PROTO_EXTENDS_FUNCTION()
};
template<typename Args, typename BidiIter>
void bind_args(let_<Args> const &args, match_results<BidiIter> &what)
{
BindArgs()(args, 0, what);
}
typedef boost::proto::functional::make_expr<proto::tag::function, proto::default_domain> make_function;
}
namespace op
{
/// \brief \c at is a PolymorphicFunctionObject for indexing into a sequence
struct at
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Cont, typename Idx>
struct result<This(Cont &, Idx)>
{
typedef typename Cont::reference type;
};
template<typename This, typename Cont, typename Idx>
struct result<This(Cont const &, Idx)>
{
typedef typename Cont::const_reference type;
};
template<typename This, typename Cont, typename Idx>
struct result<This(Cont, Idx)>
{
typedef typename Cont::const_reference type;
};
/// \pre \c Cont is a model of RandomAccessSequence
/// \param c The RandomAccessSequence to index into
/// \param idx The index
/// \return <tt>c[idx]</tt>
template<typename Cont, typename Idx>
typename Cont::reference operator()(Cont &c, Idx idx BOOST_PROTO_DISABLE_IF_IS_CONST(Cont)) const
{
return c[idx];
}
/// \overload
///
template<typename Cont, typename Idx>
typename Cont::const_reference operator()(Cont const &c, Idx idx) const
{
return c[idx];
}
};
/// \brief \c push is a PolymorphicFunctionObject for pushing an element into a container.
struct push
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \param seq The sequence into which the value should be pushed.
/// \param val The value to push into the sequence.
/// \brief Equivalent to <tt>seq.push(val)</tt>.
/// \return \c void
template<typename Sequence, typename Value>
void operator()(Sequence &seq, Value const &val) const
{
seq.push(val);
}
};
/// \brief \c push_back is a PolymorphicFunctionObject for pushing an element into the back of a container.
struct push_back
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \param seq The sequence into which the value should be pushed.
/// \param val The value to push into the sequence.
/// \brief Equivalent to <tt>seq.push_back(val)</tt>.
/// \return \c void
template<typename Sequence, typename Value>
void operator()(Sequence &seq, Value const &val) const
{
seq.push_back(val);
}
};
/// \brief \c push_front is a PolymorphicFunctionObject for pushing an element into the front of a container.
struct push_front
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \param seq The sequence into which the value should be pushed.
/// \param val The value to push into the sequence.
/// \brief Equivalent to <tt>seq.push_front(val)</tt>.
/// \return \c void
template<typename Sequence, typename Value>
void operator()(Sequence &seq, Value const &val) const
{
seq.push_front(val);
}
};
/// \brief \c pop is a PolymorphicFunctionObject for popping an element from a container.
struct pop
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \param seq The sequence from which to pop.
/// \brief Equivalent to <tt>seq.pop()</tt>.
/// \return \c void
template<typename Sequence>
void operator()(Sequence &seq) const
{
seq.pop();
}
};
/// \brief \c pop_back is a PolymorphicFunctionObject for popping an element from the back of a container.
struct pop_back
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \param seq The sequence from which to pop.
/// \brief Equivalent to <tt>seq.pop_back()</tt>.
/// \return \c void
template<typename Sequence>
void operator()(Sequence &seq) const
{
seq.pop_back();
}
};
/// \brief \c pop_front is a PolymorphicFunctionObject for popping an element from the front of a container.
struct pop_front
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \param seq The sequence from which to pop.
/// \brief Equivalent to <tt>seq.pop_front()</tt>.
/// \return \c void
template<typename Sequence>
void operator()(Sequence &seq) const
{
seq.pop_front();
}
};
/// \brief \c front is a PolymorphicFunctionObject for fetching the front element of a container.
struct front
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Sequence>
struct result<This(Sequence)>
{
typedef typename remove_reference<Sequence>::type sequence_type;
typedef
typename mpl::if_c<
is_const<sequence_type>::value
, typename sequence_type::const_reference
, typename sequence_type::reference
>::type
type;
};
/// \param seq The sequence from which to fetch the front.
/// \return <tt>seq.front()</tt>
template<typename Sequence>
typename result<front(Sequence &)>::type operator()(Sequence &seq) const
{
return seq.front();
}
};
/// \brief \c back is a PolymorphicFunctionObject for fetching the back element of a container.
struct back
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Sequence>
struct result<This(Sequence)>
{
typedef typename remove_reference<Sequence>::type sequence_type;
typedef
typename mpl::if_c<
is_const<sequence_type>::value
, typename sequence_type::const_reference
, typename sequence_type::reference
>::type
type;
};
/// \param seq The sequence from which to fetch the back.
/// \return <tt>seq.back()</tt>
template<typename Sequence>
typename result<back(Sequence &)>::type operator()(Sequence &seq) const
{
return seq.back();
}
};
/// \brief \c top is a PolymorphicFunctionObject for fetching the top element of a stack.
struct top
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Sequence>
struct result<This(Sequence)>
{
typedef typename remove_reference<Sequence>::type sequence_type;
typedef
typename mpl::if_c<
is_const<sequence_type>::value
, typename sequence_type::value_type const &
, typename sequence_type::value_type &
>::type
type;
};
/// \param seq The sequence from which to fetch the top.
/// \return <tt>seq.top()</tt>
template<typename Sequence>
typename result<top(Sequence &)>::type operator()(Sequence &seq) const
{
return seq.top();
}
};
/// \brief \c first is a PolymorphicFunctionObject for fetching the first element of a pair.
struct first
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Pair>
struct result<This(Pair)>
{
typedef typename remove_reference<Pair>::type::first_type type;
};
/// \param p The pair from which to fetch the first element.
/// \return <tt>p.first</tt>
template<typename Pair>
typename Pair::first_type operator()(Pair const &p) const
{
return p.first;
}
};
/// \brief \c second is a PolymorphicFunctionObject for fetching the second element of a pair.
struct second
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Pair>
struct result<This(Pair)>
{
typedef typename remove_reference<Pair>::type::second_type type;
};
/// \param p The pair from which to fetch the second element.
/// \return <tt>p.second</tt>
template<typename Pair>
typename Pair::second_type operator()(Pair const &p) const
{
return p.second;
}
};
/// \brief \c matched is a PolymorphicFunctionObject for assessing whether a \c sub_match object
/// matched or not.
struct matched
{
BOOST_PROTO_CALLABLE()
typedef bool result_type;
/// \param sub The \c sub_match object.
/// \return <tt>sub.matched</tt>
template<typename Sub>
bool operator()(Sub const &sub) const
{
return sub.matched;
}
};
/// \brief \c length is a PolymorphicFunctionObject for fetching the length of \c sub_match.
struct length
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Sub>
struct result<This(Sub)>
{
typedef typename remove_reference<Sub>::type::difference_type type;
};
/// \param sub The \c sub_match object.
/// \return <tt>sub.length()</tt>
template<typename Sub>
typename Sub::difference_type operator()(Sub const &sub) const
{
return sub.length();
}
};
/// \brief \c str is a PolymorphicFunctionObject for turning a \c sub_match into an
/// equivalent \c std::string.
struct str
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Sub>
struct result<This(Sub)>
{
typedef typename remove_reference<Sub>::type::string_type type;
};
/// \param sub The \c sub_match object.
/// \return <tt>sub.str()</tt>
template<typename Sub>
typename Sub::string_type operator()(Sub const &sub) const
{
return sub.str();
}
};
// This codifies the return types of the various insert member
// functions found in sequence containers, the 2 flavors of
// associative containers, and strings.
//
/// \brief \c insert is a PolymorphicFunctionObject for inserting a value or a
/// sequence of values into a sequence container, an associative
/// container, or a string.
struct insert
{
BOOST_PROTO_CALLABLE()
/// INTERNAL ONLY
///
struct detail
{
template<typename Sig, typename EnableIf = void>
struct result_detail
{};
// assoc containers
template<typename This, typename Cont, typename Value>
struct result_detail<This(Cont, Value), void>
{
typedef typename remove_reference<Cont>::type cont_type;
typedef typename remove_reference<Value>::type value_type;
static cont_type &scont_;
static value_type &svalue_;
typedef char yes_type;
typedef char (&no_type)[2];
static yes_type check_insert_return(typename cont_type::iterator);
static no_type check_insert_return(std::pair<typename cont_type::iterator, bool>);
BOOST_STATIC_CONSTANT(bool, is_iterator = (sizeof(yes_type) == sizeof(check_insert_return(scont_.insert(svalue_)))));
typedef
typename mpl::if_c<
is_iterator
, typename cont_type::iterator
, std::pair<typename cont_type::iterator, bool>
>::type
type;
};
// sequence containers, assoc containers, strings
template<typename This, typename Cont, typename It, typename Value>
struct result_detail<This(Cont, It, Value),
typename disable_if<
mpl::or_<
is_integral<typename remove_cv<typename remove_reference<It>::type>::type>
, is_same<
typename remove_cv<typename remove_reference<It>::type>::type
, typename remove_cv<typename remove_reference<Value>::type>::type
>
>
>::type
>
{
typedef typename remove_reference<Cont>::type::iterator type;
};
// strings
template<typename This, typename Cont, typename Size, typename T>
struct result_detail<This(Cont, Size, T),
typename enable_if<
is_integral<typename remove_cv<typename remove_reference<Size>::type>::type>
>::type
>
{
typedef typename remove_reference<Cont>::type &type;
};
// assoc containers
template<typename This, typename Cont, typename It>
struct result_detail<This(Cont, It, It), void>
{
typedef void type;
};
// sequence containers, strings
template<typename This, typename Cont, typename It, typename Size, typename Value>
struct result_detail<This(Cont, It, Size, Value),
typename disable_if<
is_integral<typename remove_cv<typename remove_reference<It>::type>::type>
>::type
>
{
typedef void type;
};
// strings
template<typename This, typename Cont, typename Size, typename A0, typename A1>
struct result_detail<This(Cont, Size, A0, A1),
typename enable_if<
is_integral<typename remove_cv<typename remove_reference<Size>::type>::type>
>::type
>
{
typedef typename remove_reference<Cont>::type &type;
};
// strings
template<typename This, typename Cont, typename Pos0, typename String, typename Pos1, typename Length>
struct result_detail<This(Cont, Pos0, String, Pos1, Length)>
{
typedef typename remove_reference<Cont>::type &type;
};
};
template<typename Sig>
struct result
{
typedef typename detail::result_detail<Sig>::type type;
};
/// \overload
///
template<typename Cont, typename A0>
typename result<insert(Cont &, A0 const &)>::type
operator()(Cont &cont, A0 const &a0) const
{
return cont.insert(a0);
}
/// \overload
///
template<typename Cont, typename A0, typename A1>
typename result<insert(Cont &, A0 const &, A1 const &)>::type
operator()(Cont &cont, A0 const &a0, A1 const &a1) const
{
return cont.insert(a0, a1);
}
/// \overload
///
template<typename Cont, typename A0, typename A1, typename A2>
typename result<insert(Cont &, A0 const &, A1 const &, A2 const &)>::type
operator()(Cont &cont, A0 const &a0, A1 const &a1, A2 const &a2) const
{
return cont.insert(a0, a1, a2);
}
/// \param cont The container into which to insert the element(s)
/// \param a0 A value, iterator, or count
/// \param a1 A value, iterator, string, count, or character
/// \param a2 A value, iterator, or count
/// \param a3 A count
/// \return \li For the form <tt>insert()(cont, a0)</tt>, return <tt>cont.insert(a0)</tt>.
/// \li For the form <tt>insert()(cont, a0, a1)</tt>, return <tt>cont.insert(a0, a1)</tt>.
/// \li For the form <tt>insert()(cont, a0, a1, a2)</tt>, return <tt>cont.insert(a0, a1, a2)</tt>.
/// \li For the form <tt>insert()(cont, a0, a1, a2, a3)</tt>, return <tt>cont.insert(a0, a1, a2, a3)</tt>.
template<typename Cont, typename A0, typename A1, typename A2, typename A3>
typename result<insert(Cont &, A0 const &, A1 const &, A2 const &, A3 const &)>::type
operator()(Cont &cont, A0 const &a0, A1 const &a1, A2 const &a2, A3 const &a3) const
{
return cont.insert(a0, a1, a2, a3);
}
};
/// \brief \c make_pair is a PolymorphicFunctionObject for building a \c std::pair out of two parameters
struct make_pair
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename First, typename Second>
struct result<This(First, Second)>
{
/// \brief For exposition only
typedef typename decay<First>::type first_type;
/// \brief For exposition only
typedef typename decay<Second>::type second_type;
typedef std::pair<first_type, second_type> type;
};
/// \param first The first element of the pair
/// \param second The second element of the pair
/// \return <tt>std::make_pair(first, second)</tt>
template<typename First, typename Second>
std::pair<First, Second> operator()(First const &first, Second const &second) const
{
return std::make_pair(first, second);
}
};
/// \brief \c as\<\> is a PolymorphicFunctionObject for lexically casting a parameter to a different type.
/// \tparam T The type to which to lexically cast the parameter.
template<typename T>
struct as
{
BOOST_PROTO_CALLABLE()
typedef T result_type;
/// \param val The value to lexically cast.
/// \return <tt>boost::lexical_cast\<T\>(val)</tt>
template<typename Value>
T operator()(Value const &val) const
{
return boost::lexical_cast<T>(val);
}
// Hack around some limitations in boost::lexical_cast
/// INTERNAL ONLY
T operator()(csub_match const &val) const
{
return val.matched
? boost::lexical_cast<T>(boost::make_iterator_range(val.first, val.second))
: boost::lexical_cast<T>("");
}
#ifndef BOOST_XPRESSIVE_NO_WREGEX
/// INTERNAL ONLY
T operator()(wcsub_match const &val) const
{
return val.matched
? boost::lexical_cast<T>(boost::make_iterator_range(val.first, val.second))
: boost::lexical_cast<T>("");
}
#endif
/// INTERNAL ONLY
template<typename BidiIter>
T operator()(sub_match<BidiIter> const &val) const
{
// If this assert fires, you're trying to coerce a sequences of non-characters
// to some other type. Xpressive doesn't know how to do that.
typedef typename iterator_value<BidiIter>::type char_type;
BOOST_MPL_ASSERT_MSG(
(xpressive::detail::is_char<char_type>::value)
, CAN_ONLY_CONVERT_FROM_CHARACTER_SEQUENCES
, (char_type)
);
return this->impl(val, xpressive::detail::is_string_iterator<BidiIter>());
}
private:
/// INTERNAL ONLY
template<typename RandIter>
T impl(sub_match<RandIter> const &val, mpl::true_) const
{
return val.matched
? boost::lexical_cast<T>(boost::make_iterator_range(&*val.first, &*val.first + (val.second - val.first)))
: boost::lexical_cast<T>("");
}
/// INTERNAL ONLY
template<typename BidiIter>
T impl(sub_match<BidiIter> const &val, mpl::false_) const
{
return boost::lexical_cast<T>(val.str());
}
};
/// \brief \c static_cast_\<\> is a PolymorphicFunctionObject for statically casting a parameter to a different type.
/// \tparam T The type to which to statically cast the parameter.
template<typename T>
struct static_cast_
{
BOOST_PROTO_CALLABLE()
typedef T result_type;
/// \param val The value to statically cast.
/// \return <tt>static_cast\<T\>(val)</tt>
template<typename Value>
T operator()(Value const &val) const
{
return static_cast<T>(val);
}
};
/// \brief \c dynamic_cast_\<\> is a PolymorphicFunctionObject for dynamically casting a parameter to a different type.
/// \tparam T The type to which to dynamically cast the parameter.
template<typename T>
struct dynamic_cast_
{
BOOST_PROTO_CALLABLE()
typedef T result_type;
/// \param val The value to dynamically cast.
/// \return <tt>dynamic_cast\<T\>(val)</tt>
template<typename Value>
T operator()(Value const &val) const
{
return dynamic_cast<T>(val);
}
};
/// \brief \c const_cast_\<\> is a PolymorphicFunctionObject for const-casting a parameter to a cv qualification.
/// \tparam T The type to which to const-cast the parameter.
template<typename T>
struct const_cast_
{
BOOST_PROTO_CALLABLE()
typedef T result_type;
/// \param val The value to const-cast.
/// \pre Types \c T and \c Value differ only in cv-qualification.
/// \return <tt>const_cast\<T\>(val)</tt>
template<typename Value>
T operator()(Value const &val) const
{
return const_cast<T>(val);
}
};
/// \brief \c construct\<\> is a PolymorphicFunctionObject for constructing a new object.
/// \tparam T The type of the object to construct.
template<typename T>
struct construct
{
BOOST_PROTO_CALLABLE()
typedef T result_type;
/// \overload
T operator()() const
{
return T();
}
/// \overload
template<typename A0>
T operator()(A0 const &a0) const
{
return T(a0);
}
/// \overload
template<typename A0, typename A1>
T operator()(A0 const &a0, A1 const &a1) const
{
return T(a0, a1);
}
/// \param a0 The first argument to the constructor
/// \param a1 The second argument to the constructor
/// \param a2 The third argument to the constructor
/// \return <tt>T(a0,a1,...)</tt>
template<typename A0, typename A1, typename A2>
T operator()(A0 const &a0, A1 const &a1, A2 const &a2) const
{
return T(a0, a1, a2);
}
};
/// \brief \c throw_\<\> is a PolymorphicFunctionObject for throwing an exception.
/// \tparam Except The type of the object to throw.
template<typename Except>
struct throw_
{
BOOST_PROTO_CALLABLE()
typedef void result_type;
/// \overload
void operator()() const
{
BOOST_THROW_EXCEPTION(Except());
}
/// \overload
template<typename A0>
void operator()(A0 const &a0) const
{
BOOST_THROW_EXCEPTION(Except(a0));
}
/// \overload
template<typename A0, typename A1>
void operator()(A0 const &a0, A1 const &a1) const
{
BOOST_THROW_EXCEPTION(Except(a0, a1));
}
/// \param a0 The first argument to the constructor
/// \param a1 The second argument to the constructor
/// \param a2 The third argument to the constructor
/// \throw <tt>Except(a0,a1,...)</tt>
/// \note This function makes use of the \c BOOST_THROW_EXCEPTION macro
/// to actually throw the exception. See the documentation for the
/// Boost.Exception library.
template<typename A0, typename A1, typename A2>
void operator()(A0 const &a0, A1 const &a1, A2 const &a2) const
{
BOOST_THROW_EXCEPTION(Except(a0, a1, a2));
}
};
/// \brief \c unwrap_reference is a PolymorphicFunctionObject for unwrapping a <tt>boost::reference_wrapper\<\></tt>.
struct unwrap_reference
{
BOOST_PROTO_CALLABLE()
template<typename Sig>
struct result {};
template<typename This, typename Ref>
struct result<This(Ref)>
{
typedef typename boost::unwrap_reference<Ref>::type &type;
};
template<typename This, typename Ref>
struct result<This(Ref &)>
{
typedef typename boost::unwrap_reference<Ref>::type &type;
};
/// \param r The <tt>boost::reference_wrapper\<T\></tt> to unwrap.
/// \return <tt>static_cast\<T &\>(r)</tt>
template<typename T>
T &operator()(boost::reference_wrapper<T> r) const
{
return static_cast<T &>(r);
}
};
}
/// \brief A unary metafunction that turns an ordinary function object type into the type of
/// a deferred function object for use in xpressive semantic actions.
///
/// Use \c xpressive::function\<\> to turn an ordinary polymorphic function object type
/// into a type that can be used to declare an object for use in xpressive semantic actions.
///
/// For example, the global object \c xpressive::push_back can be used to create deferred actions
/// that have the effect of pushing a value into a container. It is defined with
/// \c xpressive::function\<\> as follows:
///
/** \code
xpressive::function<xpressive::op::push_back>::type const push_back = {};
\endcode
*/
///
/// where \c op::push_back is an ordinary function object that pushes its second argument into
/// its first. Thus defined, \c xpressive::push_back can be used in semantic actions as follows:
///
/** \code
namespace xp = boost::xpressive;
using xp::_;
std::list<int> result;
std::string str("1 23 456 7890");
xp::sregex rx = (+_d)[ xp::push_back(xp::ref(result), xp::as<int>(_) ]
>> *(' ' >> (+_d)[ xp::push_back(xp::ref(result), xp::as<int>(_) ) ]);
\endcode
*/
template<typename PolymorphicFunctionObject>
struct function
{
typedef typename proto::terminal<PolymorphicFunctionObject>::type type;
};
/// \brief \c at is a lazy PolymorphicFunctionObject for indexing into a sequence in an
/// xpressive semantic action.
function<op::at>::type const at = {{}};
/// \brief \c push is a lazy PolymorphicFunctionObject for pushing a value into a container in an
/// xpressive semantic action.
function<op::push>::type const push = {{}};
/// \brief \c push_back is a lazy PolymorphicFunctionObject for pushing a value into a container in an
/// xpressive semantic action.
function<op::push_back>::type const push_back = {{}};
/// \brief \c push_front is a lazy PolymorphicFunctionObject for pushing a value into a container in an
/// xpressive semantic action.
function<op::push_front>::type const push_front = {{}};
/// \brief \c pop is a lazy PolymorphicFunctionObject for popping the top element from a sequence in an
/// xpressive semantic action.
function<op::pop>::type const pop = {{}};
/// \brief \c pop_back is a lazy PolymorphicFunctionObject for popping the back element from a sequence in an
/// xpressive semantic action.
function<op::pop_back>::type const pop_back = {{}};
/// \brief \c pop_front is a lazy PolymorphicFunctionObject for popping the front element from a sequence in an
/// xpressive semantic action.
function<op::pop_front>::type const pop_front = {{}};
/// \brief \c top is a lazy PolymorphicFunctionObject for accessing the top element from a stack in an
/// xpressive semantic action.
function<op::top>::type const top = {{}};
/// \brief \c back is a lazy PolymorphicFunctionObject for fetching the back element of a sequence in an
/// xpressive semantic action.
function<op::back>::type const back = {{}};
/// \brief \c front is a lazy PolymorphicFunctionObject for fetching the front element of a sequence in an
/// xpressive semantic action.
function<op::front>::type const front = {{}};
/// \brief \c first is a lazy PolymorphicFunctionObject for accessing the first element of a \c std::pair\<\> in an
/// xpressive semantic action.
function<op::first>::type const first = {{}};
/// \brief \c second is a lazy PolymorphicFunctionObject for accessing the second element of a \c std::pair\<\> in an
/// xpressive semantic action.
function<op::second>::type const second = {{}};
/// \brief \c matched is a lazy PolymorphicFunctionObject for accessing the \c matched member of a \c xpressive::sub_match\<\> in an
/// xpressive semantic action.
function<op::matched>::type const matched = {{}};
/// \brief \c length is a lazy PolymorphicFunctionObject for computing the length of a \c xpressive::sub_match\<\> in an
/// xpressive semantic action.
function<op::length>::type const length = {{}};
/// \brief \c str is a lazy PolymorphicFunctionObject for converting a \c xpressive::sub_match\<\> to a \c std::basic_string\<\> in an
/// xpressive semantic action.
function<op::str>::type const str = {{}};
/// \brief \c insert is a lazy PolymorphicFunctionObject for inserting a value or a range of values into a sequence in an
/// xpressive semantic action.
function<op::insert>::type const insert = {{}};
/// \brief \c make_pair is a lazy PolymorphicFunctionObject for making a \c std::pair\<\> in an
/// xpressive semantic action.
function<op::make_pair>::type const make_pair = {{}};
/// \brief \c unwrap_reference is a lazy PolymorphicFunctionObject for unwrapping a \c boost::reference_wrapper\<\> in an
/// xpressive semantic action.
function<op::unwrap_reference>::type const unwrap_reference = {{}};
/// \brief \c value\<\> is a lazy wrapper for a value that can be used in xpressive semantic actions.
/// \tparam T The type of the value to store.
///
/// Below is an example that shows where \c <tt>value\<\></tt> is useful.
///
/** \code
sregex good_voodoo(boost::shared_ptr<int> pi)
{
using namespace boost::xpressive;
// Use val() to hold the shared_ptr by value:
sregex rex = +( _d [ ++*val(pi) ] >> '!' );
// OK, rex holds a reference count to the integer.
return rex;
}
\endcode
*/
///
/// In the above code, \c xpressive::val() is a function that returns a \c value\<\> object. Had
/// \c val() not been used here, the operation <tt>++*pi</tt> would have been evaluated eagerly
/// once, instead of lazily when the regex match happens.
template<typename T>
struct value
: proto::extends<typename proto::terminal<T>::type, value<T> >
{
/// INTERNAL ONLY
typedef proto::extends<typename proto::terminal<T>::type, value<T> > base_type;
/// \brief Store a default-constructed \c T
value()
: base_type()
{}
/// \param t The initial value.
/// \brief Store a copy of \c t.
explicit value(T const &t)
: base_type(base_type::proto_base_expr::make(t))
{}
using base_type::operator=;
/// \overload
T &get()
{
return proto::value(*this);
}
/// \brief Fetch the stored value
T const &get() const
{
return proto::value(*this);
}
};
/// \brief \c reference\<\> is a lazy wrapper for a reference that can be used in
/// xpressive semantic actions.
///
/// \tparam T The type of the referent.
///
/// Here is an example of how to use \c reference\<\> to create a lazy reference to
/// an existing object so it can be read and written in an xpressive semantic action.
///
/** \code
using namespace boost::xpressive;
std::map<std::string, int> result;
reference<std::map<std::string, int> > result_ref(result);
// Match a word and an integer, separated by =>,
// and then stuff the result into a std::map<>
sregex pair = ( (s1= +_w) >> "=>" >> (s2= +_d) )
[ result_ref[s1] = as<int>(s2) ];
\endcode
*/
template<typename T>
struct reference
: proto::extends<typename proto::terminal<reference_wrapper<T> >::type, reference<T> >
{
/// INTERNAL ONLY
typedef proto::extends<typename proto::terminal<reference_wrapper<T> >::type, reference<T> > base_type;
/// \param t Reference to object
/// \brief Store a reference to \c t
explicit reference(T &t)
: base_type(base_type::proto_base_expr::make(boost::ref(t)))
{}
using base_type::operator=;
/// \brief Fetch the stored value
T &get() const
{
return proto::value(*this).get();
}
};
/// \brief \c local\<\> is a lazy wrapper for a reference to a value that is stored within the local itself.
/// It is for use within xpressive semantic actions.
///
/// \tparam T The type of the local variable.
///
/// Below is an example of how to use \c local\<\> in semantic actions.
///
/** \code
using namespace boost::xpressive;
local<int> i(0);
std::string str("1!2!3?");
// count the exciting digits, but not the
// questionable ones.
sregex rex = +( _d [ ++i ] >> '!' );
regex_search(str, rex);
assert( i.get() == 2 );
\endcode
*/
///
/// \note As the name "local" suggests, \c local\<\> objects and the regexes
/// that refer to them should never leave the local scope. The value stored
/// within the local object will be destroyed at the end of the \c local\<\>'s
/// lifetime, and any regex objects still holding the \c local\<\> will be
/// left with a dangling reference.
template<typename T>
struct local
: detail::value_wrapper<T>
, proto::terminal<reference_wrapper<T> >::type
{
/// INTERNAL ONLY
typedef typename proto::terminal<reference_wrapper<T> >::type base_type;
/// \brief Store a default-constructed value of type \c T
local()
: detail::value_wrapper<T>()
, base_type(base_type::make(boost::ref(detail::value_wrapper<T>::value)))
{}
/// \param t The initial value.
/// \brief Store a default-constructed value of type \c T
explicit local(T const &t)
: detail::value_wrapper<T>(t)
, base_type(base_type::make(boost::ref(detail::value_wrapper<T>::value)))
{}
using base_type::operator=;
/// Fetch the wrapped value.
T &get()
{
return proto::value(*this);
}
/// \overload
T const &get() const
{
return proto::value(*this);
}
};
/// \brief \c as() is a lazy funtion for lexically casting a parameter to a different type.
/// \tparam T The type to which to lexically cast the parameter.
/// \param a The lazy value to lexically cast.
/// \return A lazy object that, when evaluated, lexically casts its argument to the desired type.
template<typename T, typename A>
typename detail::make_function::impl<op::as<T> const, A const &>::result_type const
as(A const &a)
{
return detail::make_function::impl<op::as<T> const, A const &>()((op::as<T>()), a);
}
/// \brief \c static_cast_ is a lazy funtion for statically casting a parameter to a different type.
/// \tparam T The type to which to statically cast the parameter.
/// \param a The lazy value to statically cast.
/// \return A lazy object that, when evaluated, statically casts its argument to the desired type.
template<typename T, typename A>
typename detail::make_function::impl<op::static_cast_<T> const, A const &>::result_type const
static_cast_(A const &a)
{
return detail::make_function::impl<op::static_cast_<T> const, A const &>()((op::static_cast_<T>()), a);
}
/// \brief \c dynamic_cast_ is a lazy funtion for dynamically casting a parameter to a different type.
/// \tparam T The type to which to dynamically cast the parameter.
/// \param a The lazy value to dynamically cast.
/// \return A lazy object that, when evaluated, dynamically casts its argument to the desired type.
template<typename T, typename A>
typename detail::make_function::impl<op::dynamic_cast_<T> const, A const &>::result_type const
dynamic_cast_(A const &a)
{
return detail::make_function::impl<op::dynamic_cast_<T> const, A const &>()((op::dynamic_cast_<T>()), a);
}
/// \brief \c dynamic_cast_ is a lazy funtion for const-casting a parameter to a different type.
/// \tparam T The type to which to const-cast the parameter.
/// \param a The lazy value to const-cast.
/// \return A lazy object that, when evaluated, const-casts its argument to the desired type.
template<typename T, typename A>
typename detail::make_function::impl<op::const_cast_<T> const, A const &>::result_type const
const_cast_(A const &a)
{
return detail::make_function::impl<op::const_cast_<T> const, A const &>()((op::const_cast_<T>()), a);
}
/// \brief Helper for constructing \c value\<\> objects.
/// \return <tt>value\<T\>(t)</tt>
template<typename T>
value<T> const val(T const &t)
{
return value<T>(t);
}
/// \brief Helper for constructing \c reference\<\> objects.
/// \return <tt>reference\<T\>(t)</tt>
template<typename T>
reference<T> const ref(T &t)
{
return reference<T>(t);
}
/// \brief Helper for constructing \c reference\<\> objects that
/// store a reference to const.
/// \return <tt>reference\<T const\>(t)</tt>
template<typename T>
reference<T const> const cref(T const &t)
{
return reference<T const>(t);
}
/// \brief For adding user-defined assertions to your regular expressions.
///
/// \param t The UnaryPredicate object or Boolean semantic action.
///
/// A \RefSect{user_s_guide.semantic_actions_and_user_defined_assertions.user_defined_assertions,user-defined assertion}
/// is a kind of semantic action that evaluates
/// a Boolean lambda and, if it evaluates to false, causes the match to
/// fail at that location in the string. This will cause backtracking,
/// so the match may ultimately succeed.
///
/// To use \c check() to specify a user-defined assertion in a regex, use the
/// following syntax:
///
/** \code
sregex s = (_d >> _d)[check( XXX )]; // XXX is a custom assertion
\endcode
*/
///
/// The assertion is evaluated with a \c sub_match\<\> object that delineates
/// what part of the string matched the sub-expression to which the assertion
/// was attached.
///
/// \c check() can be used with an ordinary predicate that takes a
/// \c sub_match\<\> object as follows:
///
/** \code
// A predicate that is true IFF a sub-match is
// either 3 or 6 characters long.
struct three_or_six
{
bool operator()(ssub_match const &sub) const
{
return sub.length() == 3 || sub.length() == 6;
}
};
// match words of 3 characters or 6 characters.
sregex rx = (bow >> +_w >> eow)[ check(three_or_six()) ] ;
\endcode
*/
///
/// Alternately, \c check() can be used to define inline custom
/// assertions with the same syntax as is used to define semantic
/// actions. The following code is equivalent to above:
///
/** \code
// match words of 3 characters or 6 characters.
sregex rx = (bow >> +_w >> eow)[ check(length(_)==3 || length(_)==6) ] ;
\endcode
*/
///
/// Within a custom assertion, \c _ is a placeholder for the \c sub_match\<\>
/// That delineates the part of the string matched by the sub-expression to
/// which the custom assertion was attached.
#ifdef BOOST_XPRESSIVE_DOXYGEN_INVOKED // A hack so Doxygen emits something more meaningful.
template<typename T>
detail::unspecified check(T const &t);
#else
proto::terminal<detail::check_tag>::type const check = {{}};
#endif
/// \brief For binding local variables to placeholders in semantic actions when
/// constructing a \c regex_iterator or a \c regex_token_iterator.
///
/// \param args A set of argument bindings, where each argument binding is an assignment
/// expression, the left hand side of which must be an instance of \c placeholder\<X\>
/// for some \c X, and the right hand side is an lvalue of type \c X.
///
/// \c xpressive::let() serves the same purpose as <tt>match_results::let()</tt>;
/// that is, it binds a placeholder to a local value. The purpose is to allow a
/// regex with semantic actions to be defined that refers to objects that do not yet exist.
/// Rather than referring directly to an object, a semantic action can refer to a placeholder,
/// and the value of the placeholder can be specified later with a <em>let expression</em>.
/// The <em>let expression</em> created with \c let() is passed to the constructor of either
/// \c regex_iterator or \c regex_token_iterator.
///
/// See the section \RefSect{user_s_guide.semantic_actions_and_user_defined_assertions.referring_to_non_local_variables, "Referring to Non-Local Variables"}
/// in the Users' Guide for more discussion.
///
/// \em Example:
///
/**
\code
// Define a placeholder for a map object:
placeholder<std::map<std::string, int> > _map;
// Match a word and an integer, separated by =>,
// and then stuff the result into a std::map<>
sregex pair = ( (s1= +_w) >> "=>" >> (s2= +_d) )
[ _map[s1] = as<int>(s2) ];
// The string to parse
std::string str("aaa=>1 bbb=>23 ccc=>456");
// Here is the actual map to fill in:
std::map<std::string, int> result;
// Create a regex_iterator to find all the matches
sregex_iterator it(str.begin(), str.end(), pair, let(_map=result));
sregex_iterator end;
// step through all the matches, and fill in
// the result map
while(it != end)
++it;
std::cout << result["aaa"] << '\n';
std::cout << result["bbb"] << '\n';
std::cout << result["ccc"] << '\n';
\endcode
*/
///
/// The above code displays:
///
/** \code{.txt}
1
23
456
\endcode
*/
#ifdef BOOST_XPRESSIVE_DOXYGEN_INVOKED // A hack so Doxygen emits something more meaningful.
template<typename...ArgBindings>
detail::unspecified let(ArgBindings const &...args);
#else
detail::let_<proto::terminal<detail::let_tag>::type> const let = {{{}}};
#endif
/// \brief For defining a placeholder to stand in for a variable a semantic action.
///
/// Use \c placeholder\<\> to define a placeholder for use in semantic actions to stand
/// in for real objects. The use of placeholders allows regular expressions with actions
/// to be defined once and reused in many contexts to read and write from objects which
/// were not available when the regex was defined.
///
/// \tparam T The type of the object for which this placeholder stands in.
/// \tparam I An optional identifier that can be used to distinguish this placeholder
/// from others that may be used in the same semantic action that happen
/// to have the same type.
///
/// You can use \c placeholder\<\> by creating an object of type \c placeholder\<T\>
/// and using that object in a semantic action exactly as you intend an object of
/// type \c T to be used.
///
/**
\code
placeholder<int> _i;
placeholder<double> _d;
sregex rex = ( some >> regex >> here )
[ ++_i, _d *= _d ];
\endcode
*/
///
/// Then, when doing a pattern match with either \c regex_search(),
/// \c regex_match() or \c regex_replace(), pass a \c match_results\<\> object that
/// contains bindings for the placeholders used in the regex object's semantic actions.
/// You can create the bindings by calling \c match_results::let as follows:
///
/**
\code
int i = 0;
double d = 3.14;
smatch what;
what.let(_i = i)
.let(_d = d);
if(regex_match("some string", rex, what))
// i and d mutated here
\endcode
*/
///
/// If a semantic action executes that contains an unbound placeholder, a exception of
/// type \c regex_error is thrown.
///
/// See the discussion for \c xpressive::let() and the
/// \RefSect{user_s_guide.semantic_actions_and_user_defined_assertions.referring_to_non_local_variables, "Referring to Non-Local Variables"}
/// section in the Users' Guide for more information.
///
/// <em>Example:</em>
///
/**
\code
// Define a placeholder for a map object:
placeholder<std::map<std::string, int> > _map;
// Match a word and an integer, separated by =>,
// and then stuff the result into a std::map<>
sregex pair = ( (s1= +_w) >> "=>" >> (s2= +_d) )
[ _map[s1] = as<int>(s2) ];
// Match one or more word/integer pairs, separated
// by whitespace.
sregex rx = pair >> *(+_s >> pair);
// The string to parse
std::string str("aaa=>1 bbb=>23 ccc=>456");
// Here is the actual map to fill in:
std::map<std::string, int> result;
// Bind the _map placeholder to the actual map
smatch what;
what.let( _map = result );
// Execute the match and fill in result map
if(regex_match(str, what, rx))
{
std::cout << result["aaa"] << '\n';
std::cout << result["bbb"] << '\n';
std::cout << result["ccc"] << '\n';
}
\endcode
*/
#ifdef BOOST_XPRESSIVE_DOXYGEN_INVOKED // A hack so Doxygen emits something more meaningful.
template<typename T, int I = 0>
struct placeholder
{
/// \param t The object to associate with this placeholder
/// \return An object of unspecified type that records the association of \c t
/// with \c *this.
detail::unspecified operator=(T &t) const;
/// \overload
detail::unspecified operator=(T const &t) const;
};
#else
template<typename T, int I, typename Dummy>
struct placeholder
{
typedef placeholder<T, I, Dummy> this_type;
typedef
typename proto::terminal<detail::action_arg<T, mpl::int_<I> > >::type
action_arg_type;
BOOST_PROTO_EXTENDS(action_arg_type, this_type, proto::default_domain)
};
#endif
/// \brief A lazy funtion for constructing objects objects of the specified type.
/// \tparam T The type of object to construct.
/// \param args The arguments to the constructor.
/// \return A lazy object that, when evaluated, returns <tt>T(xs...)</tt>, where
/// <tt>xs...</tt> is the result of evaluating the lazy arguments
/// <tt>args...</tt>.
#ifdef BOOST_XPRESSIVE_DOXYGEN_INVOKED // A hack so Doxygen emits something more meaningful.
template<typename T, typename ...Args>
detail::unspecified construct(Args const &...args);
#else
/// INTERNAL ONLY
#define BOOST_PROTO_LOCAL_MACRO(N, typename_A, A_const_ref, A_const_ref_a, a) \
template<typename X2_0 BOOST_PP_COMMA_IF(N) typename_A(N)> \
typename detail::make_function::impl< \
op::construct<X2_0> const \
BOOST_PP_COMMA_IF(N) A_const_ref(N) \
>::result_type const \
construct(A_const_ref_a(N)) \
{ \
return detail::make_function::impl< \
op::construct<X2_0> const \
BOOST_PP_COMMA_IF(N) A_const_ref(N) \
>()((op::construct<X2_0>()) BOOST_PP_COMMA_IF(N) a(N)); \
} \
\
template<typename X2_0 BOOST_PP_COMMA_IF(N) typename_A(N)> \
typename detail::make_function::impl< \
op::throw_<X2_0> const \
BOOST_PP_COMMA_IF(N) A_const_ref(N) \
>::result_type const \
throw_(A_const_ref_a(N)) \
{ \
return detail::make_function::impl< \
op::throw_<X2_0> const \
BOOST_PP_COMMA_IF(N) A_const_ref(N) \
>()((op::throw_<X2_0>()) BOOST_PP_COMMA_IF(N) a(N)); \
} \
/**/
#define BOOST_PROTO_LOCAL_a BOOST_PROTO_a ///< INTERNAL ONLY
#define BOOST_PROTO_LOCAL_LIMITS (0, BOOST_PP_DEC(BOOST_PROTO_MAX_ARITY)) ///< INTERNAL ONLY
#include BOOST_PROTO_LOCAL_ITERATE()
#endif
namespace detail
{
inline void ignore_unused_regex_actions()
{
detail::ignore_unused(xpressive::at);
detail::ignore_unused(xpressive::push);
detail::ignore_unused(xpressive::push_back);
detail::ignore_unused(xpressive::push_front);
detail::ignore_unused(xpressive::pop);
detail::ignore_unused(xpressive::pop_back);
detail::ignore_unused(xpressive::pop_front);
detail::ignore_unused(xpressive::top);
detail::ignore_unused(xpressive::back);
detail::ignore_unused(xpressive::front);
detail::ignore_unused(xpressive::first);
detail::ignore_unused(xpressive::second);
detail::ignore_unused(xpressive::matched);
detail::ignore_unused(xpressive::length);
detail::ignore_unused(xpressive::str);
detail::ignore_unused(xpressive::insert);
detail::ignore_unused(xpressive::make_pair);
detail::ignore_unused(xpressive::unwrap_reference);
detail::ignore_unused(xpressive::check);
detail::ignore_unused(xpressive::let);
}
struct mark_nbr
{
BOOST_PROTO_CALLABLE()
typedef int result_type;
int operator()(mark_placeholder m) const
{
return m.mark_number_;
}
};
struct ReplaceAlgo
: proto::or_<
proto::when<
proto::terminal<mark_placeholder>
, op::at(proto::_data, proto::call<mark_nbr(proto::_value)>)
>
, proto::when<
proto::terminal<any_matcher>
, op::at(proto::_data, proto::size_t<0>)
>
, proto::when<
proto::terminal<reference_wrapper<proto::_> >
, op::unwrap_reference(proto::_value)
>
, proto::_default<ReplaceAlgo>
>
{};
}
}}
#if BOOST_MSVC
#pragma warning(pop)
#endif
#endif // BOOST_XPRESSIVE_ACTIONS_HPP_EAN_03_22_2007