// Boost Lambda Library -- loops.hpp ----------------------------------------

// Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
// Copyright (C) 2000 Gary Powell (gary.powell@sierra.com)
//
// Permission to copy, use, sell and distribute this software is granted
// provided this copyright notice appears in all copies. 
// Permission to modify the code and to distribute modified code is granted
// provided this copyright notice appears in all copies, and a notice 
// that the code was modified is included with the copyright notice.
//
// This software is provided "as is" without express or implied warranty, 
// and with no claim as to its suitability for any purpose.
//
// For more information, see www.boost.org

// --------------------------------------------------------------------------

#if !defined(BOOST_LAMBDA_LOOPS_HPP)
#define BOOST_LAMBDA_LOOPS_HPP

#include "boost/lambda/core.hpp"

namespace boost { 
namespace lambda {

// -- loop control structure actions ----------------------

class forloop_action {};
class forloop_no_body_action {};
class whileloop_action {};
class whileloop_no_body_action {};
class dowhileloop_action {};
class dowhileloop_no_body_action {};


// For loop
template <class Arg1, class Arg2, class Arg3, class Arg4>
inline const 
lambda_functor<
  lambda_functor_base<
    forloop_action, 
    tuple<lambda_functor<Arg1>, lambda_functor<Arg2>, 
          lambda_functor<Arg3>, lambda_functor<Arg4> >
  > 
>
for_loop(const lambda_functor<Arg1>& a1, const lambda_functor<Arg2>& a2, 
         const lambda_functor<Arg3>& a3, const lambda_functor<Arg4>& a4) { 
  return 
      lambda_functor_base<
        forloop_action, 
        tuple<lambda_functor<Arg1>, lambda_functor<Arg2>, 
              lambda_functor<Arg3>, lambda_functor<Arg4> >
      > 
    ( tuple<lambda_functor<Arg1>, lambda_functor<Arg2>, 
            lambda_functor<Arg3>, lambda_functor<Arg4> >(a1, a2, a3, a4)
    );
}

// No body case.
template <class Arg1, class Arg2, class Arg3>
inline const 
lambda_functor<
  lambda_functor_base<
    forloop_no_body_action, 
    tuple<lambda_functor<Arg1>, lambda_functor<Arg2>, lambda_functor<Arg3> >
  > 
>
for_loop(const lambda_functor<Arg1>& a1, const lambda_functor<Arg2>& a2, 
         const lambda_functor<Arg3>& a3) { 
  return 
      lambda_functor_base<
        forloop_no_body_action, 
        tuple<lambda_functor<Arg1>, lambda_functor<Arg2>, 
              lambda_functor<Arg3> >
      > 
      ( tuple<lambda_functor<Arg1>, lambda_functor<Arg2>, 
               lambda_functor<Arg3> >(a1, a2, a3) );
}

// While loop
template <class Arg1, class Arg2>
inline const 
lambda_functor<
  lambda_functor_base<
    whileloop_action, 
    tuple<lambda_functor<Arg1>, lambda_functor<Arg2> >
  > 
>
while_loop(const lambda_functor<Arg1>& a1, const lambda_functor<Arg2>& a2) { 
  return 
      lambda_functor_base<
        whileloop_action, 
        tuple<lambda_functor<Arg1>, lambda_functor<Arg2> >
      > 
      ( tuple<lambda_functor<Arg1>, lambda_functor<Arg2> >(a1, a2));
}

// No body case.
template <class Arg1>
inline const 
lambda_functor<
  lambda_functor_base<
    whileloop_no_body_action, 
    tuple<lambda_functor<Arg1> >
  > 
>
while_loop(const lambda_functor<Arg1>& a1) { 
  return 
      lambda_functor_base<
        whileloop_no_body_action, 
        tuple<lambda_functor<Arg1> >
      > 
      ( tuple<lambda_functor<Arg1> >(a1) );
}


// Do While loop
template <class Arg1, class Arg2>
inline const 
lambda_functor<
  lambda_functor_base<
    dowhileloop_action, 
    tuple<lambda_functor<Arg1>, lambda_functor<Arg2> >
  > 
>
do_while_loop(const lambda_functor<Arg1>& a1, const lambda_functor<Arg2>& a2) {
  return 
      lambda_functor_base<
        dowhileloop_action, 
        tuple<lambda_functor<Arg1>, lambda_functor<Arg2> >
      > 
      ( tuple<lambda_functor<Arg1>, lambda_functor<Arg2> >(a1, a2));
}

// No body case.
template <class Arg1>
inline const 
lambda_functor<
  lambda_functor_base<
    dowhileloop_no_body_action, 
    tuple<lambda_functor<Arg1> >
  > 
>
do_while_loop(const lambda_functor<Arg1>& a1) { 
  return 
      lambda_functor_base<
        dowhileloop_no_body_action, 
        tuple<lambda_functor<Arg1> >
      > 
      ( tuple<lambda_functor<Arg1> >(a1));
}


// Control loop lambda_functor_base specializations.

// Specialization for for_loop.
template<class Args>
class 
lambda_functor_base<forloop_action, Args> {
public:
  Args args;
  template <class T> struct sig { typedef void type; };
public:
  explicit lambda_functor_base(const Args& a) : args(a) {}

  template<class RET, CALL_TEMPLATE_ARGS>
  RET call(CALL_FORMAL_ARGS) const {
    for(detail::select(boost::tuples::get<0>(args), CALL_ACTUAL_ARGS); 
        detail::select(boost::tuples::get<1>(args), CALL_ACTUAL_ARGS); 
        detail::select(boost::tuples::get<2>(args), CALL_ACTUAL_ARGS))
      
      detail::select(boost::tuples::get<3>(args), CALL_ACTUAL_ARGS);
  }
};

// No body case
template<class Args>
class 
lambda_functor_base<forloop_no_body_action, Args> {
public:
  Args args;
  template <class T> struct sig { typedef void type; };
public:
  explicit lambda_functor_base(const Args& a) : args(a) {}

  template<class RET, CALL_TEMPLATE_ARGS>
  RET call(CALL_FORMAL_ARGS) const {
    for(detail::select(boost::tuples::get<0>(args), CALL_ACTUAL_ARGS); 
        detail::select(boost::tuples::get<1>(args), CALL_ACTUAL_ARGS); 
        detail::select(boost::tuples::get<2>(args), CALL_ACTUAL_ARGS)) {}
   }
};


// Specialization for while_loop.
template<class Args>
class 
lambda_functor_base<whileloop_action, Args> {
public:
  Args args;
  template <class T> struct sig { typedef void type; };
public:
  explicit lambda_functor_base(const Args& a) : args(a) {}

  template<class RET, CALL_TEMPLATE_ARGS>
  RET call(CALL_FORMAL_ARGS) const {
    while(detail::select(boost::tuples::get<0>(args), CALL_ACTUAL_ARGS))
      
      detail::select(boost::tuples::get<1>(args), CALL_ACTUAL_ARGS);
  }
};

// No body case
template<class Args> 
class 
lambda_functor_base<whileloop_no_body_action, Args> {
public:
  Args args;
  template <class T> struct sig { typedef void type; };
public:
  explicit lambda_functor_base(const Args& a) : args(a) {}

  template<class RET, CALL_TEMPLATE_ARGS>
  RET call(CALL_FORMAL_ARGS) const {
          while(detail::select(boost::tuples::get<0>(args), CALL_ACTUAL_ARGS)) {}
  }
};

// Specialization for do_while_loop.
// Note that the first argument is the condition.
template<class Args>
class 
lambda_functor_base<dowhileloop_action, Args> {
public:
  Args args;
  template <class T> struct sig { typedef void type; };
public:
  explicit lambda_functor_base(const Args& a) : args(a) {}

  template<class RET, CALL_TEMPLATE_ARGS>
  RET call(CALL_FORMAL_ARGS) const {
    do {
      detail::select(boost::tuples::get<1>(args), CALL_ACTUAL_ARGS);      
    } while (detail::select(boost::tuples::get<0>(args), CALL_ACTUAL_ARGS) );
  }
};

// No body case
template<class Args>
class 
lambda_functor_base<dowhileloop_no_body_action, Args> {
public:
  Args args;
  template <class T> struct sig { typedef void type; };
public:
  explicit lambda_functor_base(const Args& a) : args(a) {}

  template<class RET, CALL_TEMPLATE_ARGS>
  RET call(CALL_FORMAL_ARGS) const {
          do {} while (detail::select(boost::tuples::get<0>(args), CALL_ACTUAL_ARGS) );
  }
};

  // The code below is from Joel de Guzman, some name changes etc. 
  // has been made.

/*=============================================================================
    Statements

    Phoenix V0.9
    Copyright (c) 2001-2002 Joel de Guzman

    This software is provided 'as-is', without any express or implied
    warranty. In no event will the copyright holder be held liable for
    any damages arising from the use of this software.

    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute
    it freely, subject to the following restrictions:

    1.  The origin of this software must not be misrepresented; you must
        not claim that you wrote the original software. If you use this
        software in a product, an acknowledgment in the product documentation
        would be appreciated but is not required.

    2.  Altered source versions must be plainly marked as such, and must
        not be misrepresented as being the original software.

    3.  This notice may not be removed or altered from any source
        distribution.

    URL: http://spirit.sourceforge.net/

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

///////////////////////////////////////////////////////////////////////////////
//
//  while_composite
//
//      This composite has the form:
//
//          while_(condition)
//          [
//              statement
//          ]
//
//      While the condition (an lambda_functor) evaluates to true, statement
//      (another lambda_functor) is executed. The result type of this is void.
//      Note the trailing underscore after while_.
//
///////////////////////////////////////////////////////////////////////////////
template <typename CondT, typename DoT>
struct while_composite {

    typedef while_composite<CondT, DoT> self_t;

    template <class SigArgs>
    struct sig { typedef void type; };

    while_composite(CondT const& cond_, DoT const& do__)
    :   cond(cond_), do_(do__) {}

    template <class Ret, CALL_TEMPLATE_ARGS>
    Ret call(CALL_FORMAL_ARGS) const
    {
        while (cond.internal_call(CALL_ACTUAL_ARGS))
            do_.internal_call(CALL_ACTUAL_ARGS);
    }

    CondT cond;
    DoT do_;
};

//////////////////////////////////
template <typename CondT>
struct while_gen {

    while_gen(CondT const& cond_)
    :   cond(cond_) {}

    template <typename DoT>
    lambda_functor<while_composite<
        typename as_lambda_functor<CondT>::type,
        typename as_lambda_functor<DoT>::type> >
    operator[](DoT const& do_) const
    {
        typedef while_composite<
            typename as_lambda_functor<CondT>::type,
            typename as_lambda_functor<DoT>::type>
        result;

        return result(
            to_lambda_functor(cond),
            to_lambda_functor(do_));
    }

    CondT cond;
};

//////////////////////////////////
template <typename CondT>
inline while_gen<CondT>
while_(CondT const& cond)
{
    return while_gen<CondT>(cond);
}

///////////////////////////////////////////////////////////////////////////////
//
//  do_composite
//
//      This composite has the form:
//
//          do_
//          [
//              statement
//          ]
//          .while_(condition)
//
//      While the condition (an lambda_functor) evaluates to true, statement
//      (another lambda_functor) is executed. The statement is executed at least
//      once. The result type of this is void. Note the trailing
//      underscore after do_ and the the leading dot and the trailing
//      underscore before and after .while_.
//
///////////////////////////////////////////////////////////////////////////////
template <typename DoT, typename CondT>
struct do_composite {

    typedef do_composite<DoT, CondT> self_t;

    template <class SigArgs>
    struct sig { typedef void type; };

    do_composite(DoT const& do__, CondT const& cond_)
    :   do_(do__), cond(cond_) {}

    template <class Ret, CALL_TEMPLATE_ARGS>
    Ret call(CALL_FORMAL_ARGS) const
    {
        do
            do_.internal_call(CALL_ACTUAL_ARGS);
        while (cond.internal_call(CALL_ACTUAL_ARGS));
    }

    DoT do_;
    CondT cond;
};

////////////////////////////////////
template <typename DoT>
struct do_gen2 {

    do_gen2(DoT const& do__)
    :   do_(do__) {}

    template <typename CondT>
    lambda_functor<do_composite<
        typename as_lambda_functor<DoT>::type,
        typename as_lambda_functor<CondT>::type> >
    while_(CondT const& cond) const
    {
        typedef do_composite<
            typename as_lambda_functor<DoT>::type,
            typename as_lambda_functor<CondT>::type>
        result;

        return result(
            to_lambda_functor(do_),
            to_lambda_functor(cond));
    }

    DoT do_;
};

////////////////////////////////////
struct do_gen {

    template <typename DoT>
    do_gen2<DoT>
    operator[](DoT const& do_) const
    {
        return do_gen2<DoT>(do_);
    }
};

do_gen const do_ = do_gen();

///////////////////////////////////////////////////////////////////////////////
//
//  for_composite
//
//      This statement has the form:
//
//          for_(init, condition, step)
//          [
//              statement
//          ]
//
//      Where init, condition, step and statement are all lambda_functors. init
//      is executed once before entering the for-loop. The for-loop
//      exits once condition evaluates to false. At each loop iteration,
//      step and statement is called. The result of this statement is
//      void. Note the trailing underscore after for_.
//
///////////////////////////////////////////////////////////////////////////////
template <typename InitT, typename CondT, typename StepT, typename DoT>
struct for_composite {

    template <class SigArgs>
    struct sig { typedef void type; };

    for_composite(
        InitT const& init_,
        CondT const& cond_,
        StepT const& step_,
        DoT const& do__)
    :   init(init_), cond(cond_), step(step_), do_(do__) {}

    template <class Ret, CALL_TEMPLATE_ARGS>
    Ret
    call(CALL_FORMAL_ARGS) const
    {
        for (init.internal_call(CALL_ACTUAL_ARGS); cond.internal_call(CALL_ACTUAL_ARGS); step.internal_call(CALL_ACTUAL_ARGS))
            do_.internal_call(CALL_ACTUAL_ARGS);
    }

    InitT init; CondT cond; StepT step; DoT do_; //  lambda_functors
};

//////////////////////////////////
template <typename InitT, typename CondT, typename StepT>
struct for_gen {

    for_gen(
        InitT const& init_,
        CondT const& cond_,
        StepT const& step_)
    :   init(init_), cond(cond_), step(step_) {}

    template <typename DoT>
    lambda_functor<for_composite<
        typename as_lambda_functor<InitT>::type,
        typename as_lambda_functor<CondT>::type,
        typename as_lambda_functor<StepT>::type,
        typename as_lambda_functor<DoT>::type> >
    operator[](DoT const& do_) const
    {
        typedef for_composite<
            typename as_lambda_functor<InitT>::type,
            typename as_lambda_functor<CondT>::type,
            typename as_lambda_functor<StepT>::type,
            typename as_lambda_functor<DoT>::type>
        result;

        return result(
            to_lambda_functor(init),
            to_lambda_functor(cond),
            to_lambda_functor(step),
            to_lambda_functor(do_));
    }

    InitT init; CondT cond; StepT step;
};

//////////////////////////////////
template <typename InitT, typename CondT, typename StepT>
inline for_gen<InitT, CondT, StepT>
for_(InitT const& init, CondT const& cond, StepT const& step)
{
    return for_gen<InitT, CondT, StepT>(init, cond, step);
}

} // lambda
} // boost

#endif // BOOST_LAMBDA_LOOPS_HPP
