/*=============================================================================

    Phoenix V1.2.1

    Copyright (c) 2001-2002 Joel de Guzman

    Use, modification and distribution is subject to 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 PHOENIX_PRIMITIVES_HPP

#define PHOENIX_PRIMITIVES_HPP

///////////////////////////////////////////////////////////////////////////////

#include <boost/spirit/phoenix/actor.hpp>

///////////////////////////////////////////////////////////////////////////////

namespace phoenix {

///////////////////////////////////////////////////////////////////////////////

//

//  argument class

//

//      Lazy arguments

//

//      An actor base class that extracts and returns the Nth argument

//      from the argument list passed in the 'args' tuple in the eval

//      member function (see actor.hpp). There are some predefined

//      argument constants that can be used as actors (arg1..argN).

//

//      The argument actor is a place-holder for the actual arguments

//      passed by the client. For example, wherever arg1 is seen placed

//      in a lazy function (see functions.hpp) or lazy operator (see

//      operators.hpp), this will be replaced by the actual first

//      argument in the actual function evaluation. Argument actors are

//      essentially lazy arguments. A lazy argument is a full actor in

//      its own right and can be evaluated through the actor's operator().

//

//      Example:

//

//          char        c = 'A';

//          int         i = 123;

//          const char* s = "Hello World";

//

//          cout << arg1(c) << ' ';

//          cout << arg1(i, s) << ' ';

//          cout << arg2(i, s) << ' ';

//

//       will print out "A 123 Hello World"

//

///////////////////////////////////////////////////////////////////////////////

template <int N>

struct argument {

    template <typename TupleT>

    struct result { typedef typename tuple_element<N, TupleT>::type type; };

    template <typename TupleT>

    typename tuple_element<N, TupleT>::type

    eval(TupleT const& args) const

    {

        return args[tuple_index<N>()];

    }

};

//////////////////////////////////

actor<argument<0> > const arg1 = argument<0>();

actor<argument<1> > const arg2 = argument<1>();

actor<argument<2> > const arg3 = argument<2>();

#if PHOENIX_LIMIT > 3

actor<argument<3> > const arg4 = argument<3>();

actor<argument<4> > const arg5 = argument<4>();

actor<argument<5> > const arg6 = argument<5>();

#if PHOENIX_LIMIT > 6

actor<argument<6> > const arg7 = argument<6>();

actor<argument<7> > const arg8 = argument<7>();

actor<argument<8> > const arg9 = argument<8>();

#if PHOENIX_LIMIT > 9

actor<argument<9> > const arg10 = argument<9>();

actor<argument<10> > const arg11 = argument<10>();

actor<argument<11> > const arg12 = argument<11>();

#if PHOENIX_LIMIT > 12

actor<argument<12> > const arg13 = argument<12>();

actor<argument<13> > const arg14 = argument<13>();

actor<argument<14> > const arg15 = argument<14>();

#endif

#endif

#endif

#endif

///////////////////////////////////////////////////////////////////////////////

//

//  value class

//

//      Lazy values

//

//      A bound actual parameter is kept in a value class for deferred

//      access later when needed. A value object is immutable. Value

//      objects are typically created through the val(x) free function

//      which returns a value<T> with T deduced from the type of x. x is

//      held in the value<T> object by value.

//

//      Lazy values are actors. As such, lazy values can be evaluated

//      through the actor's operator(). Such invocation gives the value's

//      identity. Example:

//

//          cout << val(3)() << val("Hello World")();

//

//      prints out "3 Hello World"

//

///////////////////////////////////////////////////////////////////////////////

template <typename T>

struct value {

    typedef typename boost::remove_reference<T>::type plain_t;

    template <typename TupleT>

    struct result { typedef plain_t const type; };

    value(plain_t val_)

    :   val(val_) {}

    template <typename TupleT>

    plain_t const

    eval(TupleT const& /*args*/) const

    {

        return val;

    }

    plain_t val;

};

//////////////////////////////////

template <typename T>

inline actor<value<T> > const

val(T v)

{

    return value<T>(v);

}

//////////////////////////////////

template <typename BaseT>

void

val(actor<BaseT> const& v);     //  This is undefined and not allowed.

///////////////////////////////////////////////////////////////////////////

//

//  Arbitrary types T are typically converted to a actor<value<T> >

//  (see as_actor<T> in actor.hpp). A specialization is also provided

//  for arrays. T[N] arrays are converted to actor<value<T const*> >.

//

///////////////////////////////////////////////////////////////////////////

template <typename T>

struct as_actor {

    typedef actor<value<T> > type;

    static type convert(T const& x)

    { return value<T>(x); }

};

//////////////////////////////////

template <typename T, int N>

struct as_actor<T[N]> {

    typedef actor<value<T const*> > type;

    static type convert(T const x[N])

    { return value<T const*>(x); }

};

///////////////////////////////////////////////////////////////////////////////

//

//  variable class

//

//      Lazy variables

//

//      A bound actual parameter may also be held by non-const reference

//      in a variable class for deferred access later when needed. A

//      variable object is mutable, i.e. its referenced variable can be

//      modified. Variable objects are typically created through the

//      var(x) free function which returns a variable<T> with T deduced

//      from the type of x. x is held in the value<T> object by

//      reference.

//

//      Lazy variables are actors. As such, lazy variables can be

//      evaluated through the actor's operator(). Such invocation gives

//      the variables's identity. Example:

//

//          int i = 3;

//          char const* s = "Hello World";

//          cout << var(i)() << var(s)();

//

//      prints out "3 Hello World"

//

//      Another free function const_(x) may also be used. const_(x) creates

//      a variable<T const&> object using a constant reference.

//

///////////////////////////////////////////////////////////////////////////////

template <typename T>

struct variable {

    template <typename TupleT>

    struct result { typedef T& type; };

    variable(T& var_)

    :   var(var_) {}

    template <typename TupleT>

    T&

    eval(TupleT const& /*args*/) const

    {

        return var;

    }

    T& var;

};

//////////////////////////////////

template <typename T>

inline actor<variable<T> > const

var(T& v)

{

    return variable<T>(v);

}

//////////////////////////////////

template <typename T>

inline actor<variable<T const> > const

const_(T const& v)

{

    return variable<T const>(v);

}

//////////////////////////////////

template <typename BaseT>

void

var(actor<BaseT> const& v);     //  This is undefined and not allowed.

//////////////////////////////////

template <typename BaseT>

void

const_(actor<BaseT> const& v);  //  This is undefined and not allowed.

///////////////////////////////////////////////////////////////////////////////

}   //  namespace phoenix

#endif