Functions

We follow the conventions below for functions. Please keep those in mind when calling Gleam functions from Nix.

1. Gleam functions with zero arguments are called with empty attribute sets. For example, a function such as below would be called with main { }, which would give you the Nix integer 5 (as per "Types").

   pub fn main() {
     5
   }
   

2. Gleam functions with one or more arguments take them positionally. For example, the function below would be called as add 1 2 and would return 3.

   pub fn add(a: Int, b: Int) -> Int {
       a + b
   }
   

Function bodies

Function bodies, just like blocks, are translated into let...in expressions. For example, the module below:

pub fn myfunc() -> Int {
  let x = 5
  let y = 10
  let z = x * y
  let w = x - z

  x + y * w
}

is translated to

let
  myfunc = { }: let x = 5; y = 10; z = x * y; w = x - z; in x + (y * w);
in
{ inherit myfunc; }