compilation_date.spn

// takes no arguments, and returns a StringLiteral AST node containing the current date formatted as a string
macro CompilationDateAsString() -> std::ASTNode * {
  // imagine that we already have date/time support in our standard library
  let cur_date = new std::Date();
  return std::StringLiteralAST(cur_date.to_string());
}

// So, the following main() function:
fn main() {
  print(@CompilationDateAsString());
}

// will be expanded to this:
fn main() {
  print("11/10/2015");
}