Hello, world!

For our first program, we'll start off simple by printing "Hello, world!" to the terminal. Create a file called hello.inko with the following contents:

import std.stdio (Stdout)

class async Main {
  fn async main {
    Stdout.new.print('Hello, world!')
  }
}

To run the program, run the following command in your terminal:

inko run hello.inko

If all went well, the output is "Hello, world!".

Explanation

Let's explore what the program does. We first encounter the following line:

import std.stdio (Stdout)

This imports the Stdout type, used for writing text to the terminal's standard output stream. After the import we encounter the following:

class async Main {
  fn async main {

  }
}

Inko uses lightweight processes (which we'll cover separately), which are defined using the syntax class async NAME { ... }. The main process is always called "Main", and is required to define an "async" instance method called "main".

The final line writes the message to STDOUT:

Stdout.new.print('Hello, world!')

Stdout.new creates a new instance of the Stdout type, and print(...) prints the message to the standard output stream.