1575 lines
59 KiB
C++
1575 lines
59 KiB
C++
///////////////////////////////////////////////////////////////////////////////
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/// \file regex_actions.hpp
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/// Defines the syntax elements of xpressive's action expressions.
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//
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// Copyright 2008 Eric Niebler. Distributed under the Boost
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// Software License, Version 1.0. (See accompanying file
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// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_XPRESSIVE_ACTIONS_HPP_EAN_03_22_2007
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#define BOOST_XPRESSIVE_ACTIONS_HPP_EAN_03_22_2007
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER) && (_MSC_VER >= 1020)
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# pragma once
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#endif
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#include <boost/config.hpp>
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#include <boost/preprocessor/punctuation/comma_if.hpp>
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#include <boost/ref.hpp>
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#include <boost/mpl/if.hpp>
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#include <boost/mpl/or.hpp>
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#include <boost/mpl/int.hpp>
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#include <boost/mpl/assert.hpp>
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#include <boost/noncopyable.hpp>
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#include <boost/lexical_cast.hpp>
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#include <boost/throw_exception.hpp>
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#include <boost/utility/enable_if.hpp>
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#include <boost/type_traits/is_same.hpp>
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#include <boost/type_traits/is_const.hpp>
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#include <boost/type_traits/is_integral.hpp>
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#include <boost/type_traits/decay.hpp>
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#include <boost/type_traits/remove_cv.hpp>
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#include <boost/type_traits/remove_reference.hpp>
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#include <boost/range/iterator_range.hpp>
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#include <boost/xpressive/detail/detail_fwd.hpp>
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#include <boost/xpressive/detail/core/state.hpp>
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#include <boost/xpressive/detail/core/matcher/attr_matcher.hpp>
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#include <boost/xpressive/detail/core/matcher/attr_end_matcher.hpp>
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#include <boost/xpressive/detail/core/matcher/attr_begin_matcher.hpp>
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#include <boost/xpressive/detail/core/matcher/predicate_matcher.hpp>
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#include <boost/xpressive/detail/utility/ignore_unused.hpp>
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#include <boost/xpressive/detail/static/type_traits.hpp>
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// These are very often needed by client code.
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#include <boost/typeof/std/map.hpp>
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#include <boost/typeof/std/string.hpp>
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// Doxygen can't handle proto :-(
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#ifndef BOOST_XPRESSIVE_DOXYGEN_INVOKED
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# include <boost/proto/core.hpp>
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# include <boost/proto/transform.hpp>
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# include <boost/xpressive/detail/core/matcher/action_matcher.hpp>
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#endif
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#if BOOST_MSVC
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#pragma warning(push)
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#pragma warning(disable : 4510) // default constructor could not be generated
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#pragma warning(disable : 4512) // assignment operator could not be generated
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#pragma warning(disable : 4610) // can never be instantiated - user defined constructor required
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#endif
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namespace boost { namespace xpressive
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{
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namespace detail
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{
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template<typename T, typename U>
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struct action_arg
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{
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typedef T type;
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typedef typename add_reference<T>::type reference;
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reference cast(void *pv) const
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{
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return *static_cast<typename remove_reference<T>::type *>(pv);
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}
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};
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template<typename T>
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struct value_wrapper
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: private noncopyable
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{
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value_wrapper()
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: value()
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{}
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value_wrapper(T const &t)
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: value(t)
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{}
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T value;
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};
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struct check_tag
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{};
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struct BindArg
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename MatchResults, typename Expr>
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struct result<This(MatchResults, Expr)>
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{
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typedef Expr type;
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};
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template<typename MatchResults, typename Expr>
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Expr const & operator ()(MatchResults &what, Expr const &expr) const
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{
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what.let(expr);
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return expr;
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}
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};
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struct let_tag
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{};
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// let(_a = b, _c = d)
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struct BindArgs
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: proto::function<
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proto::terminal<let_tag>
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, proto::vararg<
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proto::when<
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proto::assign<proto::_, proto::_>
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, proto::call<BindArg(proto::_data, proto::_)>
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>
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>
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>
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{};
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struct let_domain
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: boost::proto::domain<boost::proto::pod_generator<let_> >
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{};
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template<typename Expr>
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struct let_
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{
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BOOST_PROTO_BASIC_EXTENDS(Expr, let_<Expr>, let_domain)
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BOOST_PROTO_EXTENDS_FUNCTION()
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};
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template<typename Args, typename BidiIter>
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void bind_args(let_<Args> const &args, match_results<BidiIter> &what)
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{
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BindArgs()(args, 0, what);
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}
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typedef boost::proto::functional::make_expr<proto::tag::function, proto::default_domain> make_function;
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}
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namespace op
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{
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/// \brief \c at is a PolymorphicFunctionObject for indexing into a sequence
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struct at
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Cont, typename Idx>
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struct result<This(Cont &, Idx)>
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{
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typedef typename Cont::reference type;
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};
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template<typename This, typename Cont, typename Idx>
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struct result<This(Cont const &, Idx)>
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{
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typedef typename Cont::const_reference type;
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};
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template<typename This, typename Cont, typename Idx>
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struct result<This(Cont, Idx)>
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{
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typedef typename Cont::const_reference type;
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};
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/// \pre \c Cont is a model of RandomAccessSequence
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/// \param c The RandomAccessSequence to index into
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/// \param idx The index
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/// \return <tt>c[idx]</tt>
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template<typename Cont, typename Idx>
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typename Cont::reference operator()(Cont &c, Idx idx BOOST_PROTO_DISABLE_IF_IS_CONST(Cont)) const
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{
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return c[idx];
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}
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/// \overload
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///
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template<typename Cont, typename Idx>
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typename Cont::const_reference operator()(Cont const &c, Idx idx) const
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{
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return c[idx];
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}
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};
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/// \brief \c push is a PolymorphicFunctionObject for pushing an element into a container.
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struct push
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{
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BOOST_PROTO_CALLABLE()
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typedef void result_type;
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/// \param seq The sequence into which the value should be pushed.
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/// \param val The value to push into the sequence.
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/// \brief Equivalent to <tt>seq.push(val)</tt>.
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/// \return \c void
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template<typename Sequence, typename Value>
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void operator()(Sequence &seq, Value const &val) const
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{
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seq.push(val);
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}
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};
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/// \brief \c push_back is a PolymorphicFunctionObject for pushing an element into the back of a container.
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struct push_back
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{
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BOOST_PROTO_CALLABLE()
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typedef void result_type;
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/// \param seq The sequence into which the value should be pushed.
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/// \param val The value to push into the sequence.
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/// \brief Equivalent to <tt>seq.push_back(val)</tt>.
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/// \return \c void
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template<typename Sequence, typename Value>
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void operator()(Sequence &seq, Value const &val) const
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{
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seq.push_back(val);
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}
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};
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/// \brief \c push_front is a PolymorphicFunctionObject for pushing an element into the front of a container.
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struct push_front
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{
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BOOST_PROTO_CALLABLE()
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typedef void result_type;
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/// \param seq The sequence into which the value should be pushed.
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/// \param val The value to push into the sequence.
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/// \brief Equivalent to <tt>seq.push_front(val)</tt>.
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/// \return \c void
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template<typename Sequence, typename Value>
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void operator()(Sequence &seq, Value const &val) const
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{
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seq.push_front(val);
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}
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};
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/// \brief \c pop is a PolymorphicFunctionObject for popping an element from a container.
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struct pop
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{
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BOOST_PROTO_CALLABLE()
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typedef void result_type;
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/// \param seq The sequence from which to pop.
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/// \brief Equivalent to <tt>seq.pop()</tt>.
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/// \return \c void
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template<typename Sequence>
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void operator()(Sequence &seq) const
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{
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seq.pop();
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}
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};
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/// \brief \c pop_back is a PolymorphicFunctionObject for popping an element from the back of a container.
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struct pop_back
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{
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BOOST_PROTO_CALLABLE()
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typedef void result_type;
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/// \param seq The sequence from which to pop.
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/// \brief Equivalent to <tt>seq.pop_back()</tt>.
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/// \return \c void
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template<typename Sequence>
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void operator()(Sequence &seq) const
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{
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seq.pop_back();
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}
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};
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/// \brief \c pop_front is a PolymorphicFunctionObject for popping an element from the front of a container.
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struct pop_front
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{
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BOOST_PROTO_CALLABLE()
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typedef void result_type;
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/// \param seq The sequence from which to pop.
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/// \brief Equivalent to <tt>seq.pop_front()</tt>.
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/// \return \c void
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template<typename Sequence>
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void operator()(Sequence &seq) const
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{
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seq.pop_front();
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}
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};
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/// \brief \c front is a PolymorphicFunctionObject for fetching the front element of a container.
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struct front
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Sequence>
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struct result<This(Sequence)>
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{
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typedef typename remove_reference<Sequence>::type sequence_type;
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typedef
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typename mpl::if_c<
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is_const<sequence_type>::value
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, typename sequence_type::const_reference
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, typename sequence_type::reference
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>::type
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type;
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};
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/// \param seq The sequence from which to fetch the front.
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/// \return <tt>seq.front()</tt>
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template<typename Sequence>
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typename result<front(Sequence &)>::type operator()(Sequence &seq) const
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{
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return seq.front();
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}
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};
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/// \brief \c back is a PolymorphicFunctionObject for fetching the back element of a container.
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struct back
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Sequence>
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struct result<This(Sequence)>
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{
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typedef typename remove_reference<Sequence>::type sequence_type;
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typedef
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typename mpl::if_c<
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is_const<sequence_type>::value
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, typename sequence_type::const_reference
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, typename sequence_type::reference
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>::type
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type;
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};
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/// \param seq The sequence from which to fetch the back.
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/// \return <tt>seq.back()</tt>
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template<typename Sequence>
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typename result<back(Sequence &)>::type operator()(Sequence &seq) const
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{
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return seq.back();
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}
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};
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/// \brief \c top is a PolymorphicFunctionObject for fetching the top element of a stack.
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struct top
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Sequence>
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struct result<This(Sequence)>
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{
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typedef typename remove_reference<Sequence>::type sequence_type;
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typedef
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typename mpl::if_c<
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is_const<sequence_type>::value
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, typename sequence_type::value_type const &
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, typename sequence_type::value_type &
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>::type
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type;
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};
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/// \param seq The sequence from which to fetch the top.
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/// \return <tt>seq.top()</tt>
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template<typename Sequence>
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typename result<top(Sequence &)>::type operator()(Sequence &seq) const
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{
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return seq.top();
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}
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};
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/// \brief \c first is a PolymorphicFunctionObject for fetching the first element of a pair.
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struct first
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Pair>
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struct result<This(Pair)>
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{
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typedef typename remove_reference<Pair>::type::first_type type;
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};
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/// \param p The pair from which to fetch the first element.
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/// \return <tt>p.first</tt>
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template<typename Pair>
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typename Pair::first_type operator()(Pair const &p) const
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{
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return p.first;
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}
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};
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/// \brief \c second is a PolymorphicFunctionObject for fetching the second element of a pair.
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struct second
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Pair>
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struct result<This(Pair)>
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{
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typedef typename remove_reference<Pair>::type::second_type type;
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};
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/// \param p The pair from which to fetch the second element.
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/// \return <tt>p.second</tt>
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template<typename Pair>
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typename Pair::second_type operator()(Pair const &p) const
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{
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return p.second;
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}
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};
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/// \brief \c matched is a PolymorphicFunctionObject for assessing whether a \c sub_match object
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/// matched or not.
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struct matched
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{
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BOOST_PROTO_CALLABLE()
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typedef bool result_type;
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/// \param sub The \c sub_match object.
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/// \return <tt>sub.matched</tt>
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template<typename Sub>
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bool operator()(Sub const &sub) const
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{
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return sub.matched;
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}
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};
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/// \brief \c length is a PolymorphicFunctionObject for fetching the length of \c sub_match.
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struct length
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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template<typename This, typename Sub>
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struct result<This(Sub)>
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{
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typedef typename remove_reference<Sub>::type::difference_type type;
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};
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/// \param sub The \c sub_match object.
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/// \return <tt>sub.length()</tt>
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template<typename Sub>
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typename Sub::difference_type operator()(Sub const &sub) const
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{
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return sub.length();
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}
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};
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/// \brief \c str is a PolymorphicFunctionObject for turning a \c sub_match into an
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/// equivalent \c std::string.
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struct str
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{
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BOOST_PROTO_CALLABLE()
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template<typename Sig>
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struct result {};
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|
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template<typename This, typename Sub>
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struct result<This(Sub)>
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{
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typedef typename remove_reference<Sub>::type::string_type type;
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};
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|
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/// \param sub The \c sub_match object.
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/// \return <tt>sub.str()</tt>
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template<typename Sub>
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typename Sub::string_type operator()(Sub const &sub) const
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|
{
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return sub.str();
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|
}
|
|
};
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// This codifies the return types of the various insert member
|
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// functions found in sequence containers, the 2 flavors of
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// associative containers, and strings.
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//
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/// \brief \c insert is a PolymorphicFunctionObject for inserting a value or a
|
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/// sequence of values into a sequence container, an associative
|
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/// container, or a string.
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struct insert
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{
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BOOST_PROTO_CALLABLE()
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|
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/// INTERNAL ONLY
|
|
///
|
|
struct detail
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|
{
|
|
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>
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|
{
|
|
typedef typename remove_reference<Cont>::type cont_type;
|
|
typedef typename remove_reference<Value>::type value_type;
|
|
static cont_type &scont_;
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|
static value_type &svalue_;
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typedef char yes_type;
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|
typedef char (&no_type)[2];
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|
static yes_type check_insert_return(typename cont_type::iterator);
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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_)))));
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|
typedef
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|
typename mpl::if_c<
|
|
is_iterator
|
|
, typename cont_type::iterator
|
|
, std::pair<typename cont_type::iterator, bool>
|
|
>::type
|
|
type;
|
|
};
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|
|
|
// 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;
|
|
};
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|
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// 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
|