Function RCPP_API_CLASS

inst/include/Rcpp/Function.h:33–124

* functions */

     * functions
     */
    RCPP_API_CLASS(Function_Impl) {
    public:

        RCPP_GENERATE_CTOR_ASSIGN(Function_Impl)

        Function_Impl(SEXP x){
            switch( TYPEOF(x) ){
            case CLOSXP:
            case SPECIALSXP:
            case BUILTINSXP:
                Storage::set__(x);
                break;
            default:						// #nocov start
                const char* fmt = "Cannot convert object to a function: "
                                  "[type=%s; target=CLOSXP, SPECIALSXP, or "
                                  "BUILTINSXP].";
                throw not_compatible(fmt, Rf_type2char(TYPEOF(x)));
            }								// #nocov end
        }

        /**
         * Finds a function. By default, searches from the global environment
         *
         * @param name name of the function
         * @param env an environment where to search the function
         * @param ns name of the namespace in which to search the function
         */
        Function_Impl(const std::string& name) {
            get_function(name, R_GlobalEnv);
        }

        Function_Impl(const std::string& name, const SEXP env) {
            if (!Rf_isEnvironment(env)) {
                stop("env is not an environment");
            }
            get_function(name, env);
        }

        Function_Impl(const std::string& name, const std::string& ns) {
#if R_VERSION < R_Version(4,6,0)
            Shield<SEXP> env(Rf_findVarInFrame(R_NamespaceRegistry, Rf_install(ns.c_str())));
            if (env == R_UnboundValue)
                stop("there is no namespace called \"%s\"", ns);
#else
            Shield<SEXP> env(R_getRegisteredNamespace(ns.c_str()));
            if (env == R_NilValue)
                stop("there is no namespace called \"%s\"", ns);
#endif
            get_function(name, env);
        }

        SEXP operator()() const {
            Shield<SEXP> call(Rf_lang1(Storage::get__()));
            return Rcpp_fast_eval(call, R_GlobalEnv);
        }

        template <typename... T>
        SEXP operator()(const T&... args) const {