playing with cppfront

calculator.cpp2

struct Token {
  enum Type { integer, plus, minus, mul, div, lparen, rparen } type;
  std::string text;

  Token(Type type, const std::string& text) : type(type), text(text) {}

  friend std::ostream& operator<<(std::ostream& os, const Token& token) {
    os << " " << token.text << " ";
    return os;
  }
};



parse: (in tokens: vector<Token>) -> std::string = {
  // ast
  buffer: std::ostringstream = "";

  callback := :(inout token:_) = buffer << token.text << "<" << token.type << ">";

  for_each(tokens.begin(), tokens.end(), callback);

  return buffer.str();
}

tokenize: (in input:_) -> std::vector<Token> = {
  // lex
  res: std::vector<Token> = std::vector<Token>();

  i: int = 0;
  while (i < input.size()) {
    if input[i] == '+' {
      t: Token = Token(Token::plus, "+");
      res.push_back(t);
    }
    i++;
  }
 

/*
  for (int i = 0; i < input.size(); i++) {
    switch (input[i]) {
      case '+':
        res.push_back(Token{Token::plus, "+"});
        break;
      case '-':
        res.push_back(Token{Token::minus, "-"});
        break;
      case '*':
        res.push_back(Token{Token::mul, "*"});
        break;
      case '/':
        res.push_back(Token{Token::div, "/"});
        break;
      case '(':
        res.push_back(Token{Token::lparen, "("});
        break;
      case ')':
        res.push_back(Token{Token::rparen, ")"});
        break;
      default:
        std::ostringstream buffer;
        buffer << input[i];
        for (int j = i + 1; j < input.size(); j++) {
          if (isdigit(input[j])) {
            buffer << input[j];
            ++i;
          } else {
            res.push_back(Token{Token::integer, buffer.str()});
            break;
          }
        }
        break;
    }
  }
  */
  return res;
}

main : () -> int = {
  // 36
  input: std::string = "3 * (10 + 2)";

  std::cout << input << std::endl;

  tokenized: vector<Token>; 
  
  tokenized = tokenize(input);

  res: std::string = parse(tokenized);

  // auto res = parse(tokenize(input));

  std::cout << res << std::endl;

  // auto calc = Calculator;

  return 1;
}

notes.md

Source Directory: ./cppfront ../examples/calculator.cpp2 Examples Directory: clang++ calculator.cpp -I/Users/patrick/gitrepos/github/cppfront/include -std=c++20