Formula.cpp

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// -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; indent-tabs-mode: nil; -*-
//
// Formula.cpp: Rcpp R/C++ interface class library -- Formulae
//
// 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/>.

#include <Rcpp/Formula.h>

namespace Rcpp{
        
    Formula::Formula() : Language(){}
        
    Formula::Formula(SEXP x) : Language(){
        switch( TYPEOF( x ) ){
        case LANGSXP:
            if( ::Rf_inherits( x, "formula") ){
                setSEXP( x );
            } else{
                SEXP y = internal::convert_using_rfunction( x, "as.formula") ;
                setSEXP( y ) ;
            }
            break;
        case EXPRSXP:
        case VECSXP:
            /* lists or expression, try the first one */
            if( ::Rf_length(x) > 0 ){
                SEXP y = VECTOR_ELT( x, 0 ) ;
                if( ::Rf_inherits( y, "formula" ) ){
                    setSEXP( y ) ;  
                } else{
                    SEXP z = internal::convert_using_rfunction( y, "as.formula") ;
                    setSEXP( z ) ;
                }
            } else{
                throw not_compatible( "cannot create formula from empty list or expression" ) ; 
            }
            break;
        default:
            SEXP y = internal::convert_using_rfunction( x, "as.formula") ;
            setSEXP( y ) ;
        }
    }
        
    Formula::Formula( const std::string& code) : Language() {
        setSEXP( internal::convert_using_rfunction( ::Rf_mkString(code.c_str()), "as.formula") );       
    }
        
    Formula::Formula( const Formula& other ) : Language( other.asSexp() ){}
        
    Formula& Formula::operator=( const Formula& other ){
        setSEXP( other.asSexp() );
        return *this ;
    }
        
} // namespace Rcpp