proposal of the Nix syntax, Nis

nis.md

I propose "Nis", a new syntax for Nix.

Nix's syntax has a couple of issues. Its function invocation syntax breaks in arrays, which is fairly serious. It also involves a lot of semicolons. Neither of these things are necessary.

Nix version:

{
  outputs = inputs: let
    username = "mako";
    defaultHostname = "yoga";
    forHost = hostname: numberOfPears: moreConfig:
      inputs.nixpkgs.lib.nixosSystem {
        modules = [
          moreConfig
          (import ./harware-configuration.nix)
          {
            fruitBowl = { pears = numberOfPears; };
            inherit username;
            inherit hostname;
          }
        ];
      };
    in {
      nixosConfigurations = {
        yoga = forHost defaultHostname (4 + 2)*3 {};
    };
}

Nis version:

{
  outputs = (inputs): let
    username = "mako"
    defaultHostname = "yoga"
    forHost = (hostname numberOfPears moreConfig):
      inputs.nixpkgs.lib.nixosSystem({
        modules = [
          moreConfig
          import(./harware-configuration.nix)
          {
            fruitBowl = { pears = numberOfPears }
            inherit username
            inherit hostname
          }
        ]
      })
    in {
      nixosConfigurations = forHost(defaultHostname (4 + 2)*3 {})
    }
}

Those are the benefits. The only drawback is a potential to leave programmers a more confused when they first encounter a function that returns a function being used as if it were a function of two parameters, as a result of not having forceably introduced to the curried function signature syntax in the process of learning the syntax, but I was already pretty confused when I encountered an immediate call into a returned function, so I'm not sure how much difference this will make.

The parser's a little bit more complex, but you only have to write it once, and I might be the one who does it, and I don't mind doing it.

Whether a nix code file uses the nis or nix syntax can generally be determined from the file extension of the import. import will be easy to adapt.