// -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; indent-tabs-mode: nil; -*-
//
// Function.h: Rcpp R/C++ interface class library -- functions (also primitives and builtins)
//
// Copyright (C) 2010 - 2011 Dirk Eddelbuettel and Romain Francois
//
// This file is part of Rcpp.
//
// Rcpp is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// Rcpp is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Rcpp.  If not, see <http://www.gnu.org/licenses/>.

#ifndef Rcpp_Function_h
#define Rcpp_Function_h

#include <RcppCommon.h>

#include <Rcpp/grow.h>
#include <Rcpp/RObject.h>

namespace Rcpp{ 

    /** 
     * functions
     */
    class Function : public RObject{
    public:

        /**
         * Attempts to convert the SEXP to a pair list
         *
         * @throw not_compatible if the SEXP could not be converted
         * to a pair list using as.pairlist
         */
        Function(SEXP lang) ;
        
        /**
         * Finds a function, searching from the global environment
         *
         * @param name name of the function
         */
        Function(const std::string& name) ;
        
        Function(const Function& other) ;
        Function& operator=(const Function& other );
        
        // /**
        //  * Finds a function, searching from a specific environment
        //  *
        //  * @param name name of the function
        //  * @param env environment where to find it
        //  */
        // Function(const std::string& name, SEXP env ) ;
        
        /**
         * calls the function with the specified arguments
         *
         * @param ...Args variable length argument list. The type of each 
         *        argument must be wrappable, meaning there need to be 
         *        a wrap function that takes this type as its parameter
         *
         */
#ifdef HAS_VARIADIC_TEMPLATES
        template<typename... Args> 
        SEXP operator()( const Args&... args) const {
            return internal::try_catch( Rf_lang2( m_sexp, pairlist(args...) ) ) ;
        }
#else
        SEXP operator()() const {
            return internal::try_catch( Rf_lang1( m_sexp  ) ) ;     
        }
        
#include <Rcpp/generated/Function__operator.h>  
#endif
        
        /**
         * Returns the environment of this function
         */
        SEXP environment() const ;
        
        /**
         * Returns the body of the function
         */
        SEXP body() const ;
         
        ~Function() ;
    };

} // namespace Rcpp

#endif
