[eru]

> How is that supposed to read as a single expression in a pure functional language?

Well, in Haskell the following is technically single expression:

    do with pkgs; [ foo ];

(Eg using 'let {with = pure; pkgs = 1; foo = 2}' makes the above type check and compile.)

But extreme nerdery and nit-picking aside, I agree that the choice of syntax in nix unfortunate here.