Example Iron program.

hello.fe

// Importing some standard modules.
import { io, http, json } from "@iron/standard";

/// # Documentation Comments
/// Documentation comments are comments that use Markdown to provide advanced
/// formatting features. With a single command, you can generate beautiful
/// documentation that uses these comments.
///
/// NOTE: You don't have to include param/return types; those are included.
///
/// # Examples
///
/// ```
/// let hello_world: String = greeting("world"); // Returns `Hello world!`
/// ```
function greeting(name: String) -> String {
  return "Hello ${ name }!";
}

/// This function is similar to greeting(), except its parameter is an Optional.
/// This syntax and behavior is inspired by Swift. Also note that it is a public
/// function which can be used when this file is imported as a module.
///
/// # Examples
///
/// ```
/// let hello = optional_greeting(); // Returns `Hello!`
/// let hello_world = optional_greeting("world"); // Returns `Hello world!`
/// ```
public function optional_greeting(name: String?) -> String {
  return "Hello ${ name? }!" // Shorthand for `name ? name : null`
}

/// This is an example of an asynchronous function, which is useful when you
/// want to fetch resources from an external system without blocking the flow
/// of your program. It also demonstrates the usage of Iron's HTTP module.
///
/// If you're familiar with JavaScript, the syntax should be very familiar
/// since it is exactly the same.
public async function fetch_resource() -> json {
  return await http.get("https://www.some-website.com/some-resource");
}

function main {
  io.print_line("Functions without parameters don't require parentheses.");
  io.print_line("All functions, however, require the `function` keyword.");

  // Retrieve the user's name.
  let name: String = io.prompt("What is your name?");
  io.print_line(greeting(name));

  // Lambda expressions.
  let lambda_result = { return "Hello world!" };
}