proxy.h

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// -*- mode: C++; c-indent-level: 4; c-basic-offset: 4; tab-width: 8 -*-
//
// proxy.h: Rcpp R/C++ interface class library -- proxies
//
// 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__vector__proxy_h
#define Rcpp__vector__proxy_h

namespace internal{
        
        template <int RTYPE> class simple_name_proxy {
        public:
                typedef ::Rcpp::Vector<RTYPE> VECTOR ;
                typedef typename ::Rcpp::traits::storage_type<RTYPE>::type CTYPE ;
                simple_name_proxy( VECTOR& v, const std::string& name_) :
                        parent(v), name(name_){} ;
                simple_name_proxy( const simple_name_proxy& other ) : 
                        parent(other.parent), name(other.name){} ;
                ~simple_name_proxy() {} ;
                
                simple_name_proxy& operator=( CTYPE rhs ){
                        set( rhs ) ;
                        return *this ;
                }
                simple_name_proxy& operator=( const simple_name_proxy& other){
                        set( other.get() ) ;
                        return *this ;
                }
                
                template <typename T>
                simple_name_proxy& operator=( const T& rhs ){
                        set( caster<T,CTYPE>(rhs) ) ;
                        return *this ;
                }
                
                // TODO: other operators +=, -=, ...
                
                operator CTYPE() const {
                         return get() ;
                }
                
                // this helps wrap, for example : wrap( x["foo"] )
                operator SEXP() const {
                        return ::Rcpp::wrap(get()) ;
                }
                
        private:
                VECTOR& parent ;
                std::string name;
                void set( CTYPE rhs ){
                        int index = 0 ;
                        try{
                                index = parent.offset(name) ;
                                parent[ index ] = rhs ;
                        } catch( const index_out_of_bounds& ex ){
                                parent.push_back( rhs, name ); 
                        }
                }
                CTYPE get() const {
                        return parent[ parent.offset(name) ];
                }
        } ;
        
        template <int RTYPE>
        class string_name_proxy{
        public:
                typedef typename ::Rcpp::Vector<RTYPE> VECTOR ;
                typedef const char* iterator ;
                typedef const char& reference ;
                
                string_name_proxy( VECTOR& v, const std::string& name_) :
                        parent(v), name(name_){} ;
                string_name_proxy( const string_name_proxy& other ) : 
                        parent(other.parent), name(other.name){} ;
                ~string_name_proxy(){} ;
                
                string_name_proxy& operator=( const std::string& rhs ){
                        set( rhs ) ;
                        return *this ;
                }
                string_name_proxy& operator=( const string_name_proxy& other){
                        set( other.get() ) ;
                        return *this ;
                }
                
                operator char* (){
                         return get() ;
                }
                
                operator SEXP(){
                        return ::Rf_mkString(get()) ;
                }
                
                inline iterator begin() { return get() ; }
                inline iterator end(){ return begin() + size() ; }
                inline reference operator[]( int i ){ return *( get() + i ) ; }
                inline int size(){ return strlen( get() ) ; }
                
        private:
                VECTOR& parent ;
                std::string name;
                void set( const std::string& rhs ){
                        int index = 0 ;
                        try{
                                index = parent.offset(name) ;
                                parent[ index ] = rhs ;
                        } catch( const index_out_of_bounds& ex ){
                                parent.push_back( rhs, name ); 
                        }
                }
                char* get(){
                        return parent[ parent.offset(name) ];
                }
                
        } ;
        
        template <int RTYPE> class generic_name_proxy {
        public:
                typedef ::Rcpp::Vector<RTYPE> VECTOR ;
                generic_name_proxy( VECTOR& v, const std::string& name_) :
                        parent(v), name(name_){
                                RCPP_DEBUG_2( "generic_name_proxy( VECTOR& = %p, const string& = %s)", v.asSexp(), name_.c_str() );
                } ;
                generic_name_proxy( const generic_name_proxy& other ) : 
                        parent(other.parent), name(other.name){} ;
                ~generic_name_proxy(){} ;
                
                generic_name_proxy& operator=( SEXP rhs ){
                        set( rhs ) ;
                        return *this ;
                }
                generic_name_proxy& operator=( const generic_name_proxy& other){
                        set( other.get() ) ;
                        return *this ;
                }
                
                template <typename T>
                generic_name_proxy& operator=( const T& rhs ){
                        set( ::Rcpp::wrap(rhs) ) ;
                        return *this ;
                }
                
                // TODO: other operators +=, -=, ...
                
                operator SEXP() const {
                         return get() ;
                }
                
                template <typename T>
                operator T() const {
                        #if RCPP_DEBUG_LEVEL > 0
                        SEXP res = get() ;
                        RCPP_DEBUG_1( "generic_name_proxy::get() = <%p> ", res ) ;
                        return ::Rcpp::as<T>( res ) ;
                        #else
                        return ::Rcpp::as<T>( get() ) ;
                        #endif
                }
                
                operator bool() const{
                    return ::Rcpp::as<bool>(get()); 
                }
                
        private:
                VECTOR& parent ;
                std::string name;
                void set( SEXP rhs ){
                        int index = 0 ;
                        try{
                                index = parent.offset(name) ;
                                parent[ index ] = rhs ;
                        } catch( const index_out_of_bounds& ex ){
                                parent.push_back( rhs, name ); 
                        }
                }
                SEXP get() const {
                        return parent[ parent.offset(name) ];
                }
        } ;
}

namespace traits {
        
        template <int RTYPE> 
        struct r_vector_name_proxy{
                typedef typename ::Rcpp::internal::simple_name_proxy<RTYPE> type ;
        } ;
        template<> struct r_vector_name_proxy<STRSXP>{
                typedef ::Rcpp::internal::string_name_proxy<STRSXP> type ;
        } ;
        template<> struct r_vector_name_proxy<VECSXP>{
                typedef ::Rcpp::internal::generic_name_proxy<VECSXP> type ;
        } ;
        template<> struct r_vector_name_proxy<EXPRSXP>{
                typedef ::Rcpp::internal::generic_name_proxy<EXPRSXP> type ;
        } ;

        template <int RTYPE>
        struct r_vector_proxy{
                typedef typename storage_type<RTYPE>::type& type ;
        } ;
        template<> struct r_vector_proxy<STRSXP> {
                typedef ::Rcpp::internal::string_proxy<STRSXP> type ;
        } ;
        template<> struct r_vector_proxy<EXPRSXP> {
                typedef ::Rcpp::internal::generic_proxy<EXPRSXP> type ;
        } ;
        template<> struct r_vector_proxy<VECSXP> {
                typedef ::Rcpp::internal::generic_proxy<VECSXP> type ;
        } ;

        template <int RTYPE>
        struct r_vector_iterator {
                typedef typename storage_type<RTYPE>::type* type ;
        };
        template <int RTYPE> struct proxy_based_iterator{
                typedef ::Rcpp::internal::Proxy_Iterator< typename r_vector_proxy<RTYPE>::type > type ;
        } ;
        template<> struct r_vector_iterator<VECSXP> : proxy_based_iterator<VECSXP>{} ;
        template<> struct r_vector_iterator<EXPRSXP> : proxy_based_iterator<EXPRSXP>{} ;
        template<> struct r_vector_iterator<STRSXP> : proxy_based_iterator<STRSXP>{} ;

}  // traits



#endif