proxy.h

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// proxy.h: Rcpp R/C++ interface class library -- proxies
//
// Copyright (C) 2010 - 2026  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 Rcpp{
namespace internal{
 
        template <int RTYPE, template <class> class StoragePolicy>
    class simple_name_proxy {
        public:
                typedef ::Rcpp::Vector<RTYPE, StoragePolicy> 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 ){
                        R_xlen_t 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, template <class> class StoragePolicy>
        class string_name_proxy{
        public:
                typedef typename ::Rcpp::Vector<RTYPE, StoragePolicy> 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* () const {
                         return get() ;
                }
 
                operator SEXP() const {
                        return ::Rf_mkString(get()) ;
                }
 
                inline iterator begin() { return get() ; }
                inline iterator end(){ return begin() + size() ; }
                inline reference operator[]( R_xlen_t i ){ return *( get() + i ) ; }
                inline R_xlen_t size(){ return strlen( get() ) ; }
 
        private:
                VECTOR& parent ;
                std::string name;
                void set( const std::string& rhs ){
                        R_xlen_t index = 0 ;
                        try{
                                index = parent.offset(name) ;
                                parent[ index ] = rhs ;
                        } catch( const index_out_of_bounds& ex ){
                                parent.push_back( rhs, name );
                        }
                }
                char* get() const {
                        return parent[ parent.offset(name) ];
                }
 
        } ;
 
        template <int RTYPE, template <class> class StoragePolicy>
        class generic_name_proxy {
        public:
                typedef ::Rcpp::Vector<RTYPE, StoragePolicy> VECTOR ;
                generic_name_proxy( VECTOR& v, const std::string& name_) :
                        parent(v), name(name_){}
                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(Shield<SEXP>(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
                }
 
        private:
                VECTOR& parent ;
                std::string name;
                void set( SEXP rhs ){
                        R_xlen_t index = 0 ;
                        try{
                                index = parent.offset(name) ;
                                parent[ index ] = rhs ;  // #nocov
                        } 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, template <class> class StoragePolicy>
        struct r_vector_name_proxy{
                typedef typename ::Rcpp::internal::simple_name_proxy<RTYPE, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_name_proxy<STRSXP, StoragePolicy>{
                typedef ::Rcpp::internal::string_name_proxy<STRSXP, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_name_proxy<VECSXP, StoragePolicy>{
                typedef ::Rcpp::internal::generic_name_proxy<VECSXP, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_name_proxy<EXPRSXP, StoragePolicy>{
                typedef ::Rcpp::internal::generic_name_proxy<EXPRSXP, StoragePolicy> type ;
        } ;
 
        template <int RTYPE, template <class> class StoragePolicy>
        struct r_vector_proxy{
                typedef typename storage_type<RTYPE>::type& type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_proxy<STRSXP, StoragePolicy> {
                typedef ::Rcpp::internal::string_proxy<STRSXP, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_proxy<EXPRSXP, StoragePolicy> {
                typedef ::Rcpp::internal::generic_proxy<EXPRSXP, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_proxy<VECSXP, StoragePolicy> {
                typedef ::Rcpp::internal::generic_proxy<VECSXP, StoragePolicy> type ;
        } ;
 
        template <int RTYPE, template <class> class StoragePolicy>
        struct r_vector_const_proxy{
                typedef const typename storage_type<RTYPE>::type& type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_const_proxy<STRSXP, StoragePolicy> {
                typedef ::Rcpp::internal::const_string_proxy<STRSXP, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_const_proxy<VECSXP, StoragePolicy> {
                typedef ::Rcpp::internal::const_generic_proxy<VECSXP, StoragePolicy> type ;
        } ;
        template<template <class> class StoragePolicy>
        struct r_vector_const_proxy<EXPRSXP, StoragePolicy> {
                typedef ::Rcpp::internal::const_generic_proxy<EXPRSXP, StoragePolicy> type ;
        } ;
 
        template <int RTYPE, template <class> class StoragePolicy>
        struct r_vector_iterator {
                typedef typename storage_type<RTYPE>::type* type ;
        };
        template <int RTYPE, template <class> class StoragePolicy>
        struct r_vector_const_iterator {
                typedef const typename storage_type<RTYPE>::type* type ;
        };
 
        template <int RTYPE, template <class> class StoragePolicy>
        struct proxy_based_iterator{
                typedef ::Rcpp::internal::Proxy_Iterator< typename r_vector_proxy<RTYPE, StoragePolicy>::type > type ;
        } ;
        template<template <class> class StoragePolicy> struct r_vector_iterator<VECSXP, StoragePolicy> : proxy_based_iterator<VECSXP, StoragePolicy>{} ;
        template<template <class> class StoragePolicy> struct r_vector_iterator<EXPRSXP, StoragePolicy> : proxy_based_iterator<EXPRSXP, StoragePolicy>{} ;
        template<template <class> class StoragePolicy> struct r_vector_iterator<STRSXP, StoragePolicy> : proxy_based_iterator<STRSXP, StoragePolicy>{} ;
 
        template <int RTYPE, template <class> class StoragePolicy>
        struct proxy_based_const_iterator{
                typedef ::Rcpp::internal::Proxy_Iterator< typename r_vector_const_proxy<RTYPE, StoragePolicy>::type > type ;
        } ;
        template<template <class> class StoragePolicy> struct r_vector_const_iterator<VECSXP, StoragePolicy> : proxy_based_const_iterator<VECSXP, StoragePolicy>{} ;
        template<template <class> class StoragePolicy> struct r_vector_const_iterator<EXPRSXP, StoragePolicy> : proxy_based_const_iterator<EXPRSXP, StoragePolicy>{} ;
        template<template <class> class StoragePolicy> struct r_vector_const_iterator<STRSXP, StoragePolicy> : proxy_based_const_iterator<STRSXP, StoragePolicy>{} ;
 
}  // traits
}
 
#endif