Function cppNumericArgToRArg

src/attributes.cpp:2610–2638

convert a C++ numeric argument to an R argument value (returns empty string if no conversion is possible)

        // convert a C++ numeric argument to an R argument value
        // (returns empty string if no conversion is possible)
        std::string cppNumericArgToRArg(const std::string& type,
                                        const std::string& cppArg) {
            // check for a number
            double num;
            std::stringstream argStream(cppArg);
            if ((argStream >> num)) {

                // L suffix means return the value literally
                if (!argStream.eof()) {
                    std::string suffix;
                    argStream >> suffix;
                    if (argStream.eof() && suffix == "L")
                        return cppArg;
                }

                // no decimal and the type isn't explicitly double or
                // float means integer
                if (cppArg.find('.') == std::string::npos &&
                    type != "double" && type != "float")
                    return cppArg + "L";

                // otherwise return arg literally
                else
                    return cppArg;
            }
            else {
                return std::string();
            }
        }

        // convert a C++ ::create style argument value to an R argument
        // value (returns empty string if no conversion is possible)