Associative function application in Nix lang

Development Nix
1

In some languages (such as Ruby), function application is right associative:

def half x
  x / 2
end
half half half 16 # => 2

Whereas, function application in Nix is left associative. However, one can do this:

let
  makeAssociative = f: x: if builtins.isFunction x then makeAssociative (y: f (x y)) else f x;

  half = makeAssociative (x: x / 2);
in half half half 16 # => 2
2

With the pipe-operators experimental feature enabled, you could also write:

half <| half <| half 16

This has the advantage of being unambiguous for the reader.

3

Based on some prior discussions, it doesn’t seem like that operator is as likely to be kept as its “forward” counterpart.

16 |> half |> half |> half

(And I really wish <|and |> were more like function composition.)