2. Hello World

The traditional "Hello World!" program implemented in Som looks as follows:

from std::io use puts

let main = puts "Hello, World!"

Let's break this down line by line.

The code starts with an import statement. Since we want to output, or "print" a string, we'll need to import the function that allows us to do that. In this case, that's the function puts from the io module of the standard library.

Next is the value binding of main. Every Som program needs to define a value called main, which is where that program's execution starts. In this case, all that main does is use the imported puts function to print a string.

And that's it! Since Som is designed to be easy to use, there's practically no boiler-plate needed; As long as there's an entrypoint like main the program will run!

Now let's test the program by compiling and executing it. If you haven't installed the compiler yet, follow the installation instructions first. After installing the compiler, save the program as hello_world.som and then invoke somc. You can then run the resulting executable:

$ # Linux or MacOS
$ somc hello_world.som
$ ./hello_world
Hello World!
$

> # Windows
> somc.exe hello_world.som
> ./hello_world.exe
Hello World!
>