用C++实现类似Python的简单编程语言：语法解析与代码生成

以下是使用C++截取字符串的方式实现一门简单编程语言的示例代码：

#include <iostream>
#include <fstream>
#include <string>

int main() {
    std::string code = R"(

def add(a, b):
    return a + b

result = add(3, 5)
print(result)

)";

    std::ofstream outputFile("code.cpp");
    if (outputFile.is_open()) {
        outputFile << R"(#include <iostream>

int add(int a, int b) {
    return a + b;
}

int main() {
)";
        std::size_t pos = 0;
        std::string delimiter = "\n";
        std::string line;
        while ((pos = code.find(delimiter)) != std::string::npos) {
            line = code.substr(0, pos);
            code.erase(0, pos + delimiter.length());
            if (line.find("def") != std::string::npos) {
                // Function definition
                std::size_t startPos = line.find("def") + 4;
                std::size_t endPos = line.find("(");
                std::string functionName = line.substr(startPos, endPos - startPos);

                std::size_t colonPos = line.find(":");
                std::string returnType = line.substr(colonPos + 1);
                std::string functionBody = "";
                std::string indentation = "    ";
                std::string functionParams = line.substr(endPos + 1, colonPos - endPos - 1);

                std::string params = "";
                std::size_t commaPos = 0;
                while ((commaPos = functionParams.find(",")) != std::string::npos) {
                    std::string param = functionParams.substr(0, commaPos);
                    params += "int " + param + ", ";
                    functionParams.erase(0, commaPos + 2);
                }
                params += "int " + functionParams;

                outputFile << indentation << returnType << " " << functionName << "(" << params << ") {
";
                while (code.find(indentation) == 0) {
                    std::size_t newLinePos = code.find("\n");
                    std::string statement = code.substr(indentation.length(), newLinePos - indentation.length());
                    code.erase(0, newLinePos + 1);
                    outputFile << indentation << statement << "\n";
                }
                outputFile << "}
\n";
            }
            else if (line.find("=") != std::string::npos) {
                // Variable assignment
                std::size_t equalsPos = line.find("=");
                std::string variableName = line.substr(0, equalsPos);
                std::string variableValue = line.substr(equalsPos + 1);

                outputFile << "int " << variableName << " = " << variableValue << ";\n";
            }
            else if (line.find("print") != std::string::npos) {
                // Print statement
                std::size_t openParenPos = line.find("(");
                std::size_t closeParenPos = line.find(")");
                std::string printValue = line.substr(openParenPos + 1, closeParenPos - openParenPos - 1);

                outputFile << "std::cout << " << printValue << " << std::endl;\n";
            }
        }
        outputFile << R"(
    return 0;
}
)";
        outputFile.close();
        std::cout << "C++ code generated successfully!" << std::endl;
    }
    else {
        std::cerr << "Failed to open output file." << std::endl;
        return 1;
    }

    return 0;
}

使用方法：

将要转换的代码放入code字符串中。
运行上述代码，它将生成名为code.cpp的C++代码文件。
编译和运行code.cpp文件即可得到相应的输出。

注意事项：

目前仅支持整数类型。
代码转换的规则仅适用于给定的示例代码，如果需要支持更多的语法或数据类型，请相应地修改代码转换的逻辑。
请确保C++编译器已正确安装并设置好环境变量。