joeml

A toy programming language inspired by ML.

main args { print "Hello World" }

Installation

npm install
npm run build

CLI Usage

After building the project, you can use the joeml CLI to convert joeml code to JavaScript:

# Process a file
npm run joeml example.jml

# Process a file with raw (non-beautified) output
npm run joeml -- -r example.jml

# Show help
npm run joeml -- --help

Example

Create a file hello.jml:

main {
  printLn "Hello, World!"
}

Then run:

npm run joeml hello.jml

This will output the generated JavaScript:

exports.main = function() {
  const io = {
    stdout: ''
  };

  function print(str) {
    io.stdout += str;
  }

  function printLn(str) {
    io.stdout += str + '\n';
  }

  function main() {
    return printLn("Hello, World!")
  };

  return function() {
    main()
    return io;
  };
}();

Language Features

• Functions with parameters
• Let expressions
• If/else expressions
• Basic arithmetic operators (+, -, *, ==, !=)
• String and number literals
• Tail call optimization

Example Program

foo n {
  n + 1
}

bar n {
  n + 2
}

main {
  foo 1 + bar 2
}