Add flake.nix

[ursi]

Just a simple flake that exposes the packages in this repo.

[toastal]

Will the lockfile need a lot of updating?

[ursi]

I don't think so. utils will never need to be updated, nixpkgs will need to be updated any time a newer version of some package is required. But I just realized the project already pins nixpkgs in pinned.nix, so I actually think using that is the way to go.

[toastal]

alternatively, this can be used without a flake file as

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    easy-purescript-nix = {
      url = "github:justinwoo/easy-purescript-nix";
      flake = false;
    };
  };
  
  outputs = { self, nixpkgs, easy-purescript-nix, ... }@inputs:
    let
      easy-ps = import easy-purescript-nix { inherit pkgs; };
    in
    {
      # ...
    };
}

[toastal]

I think this merge request is worth looking at again. Flakes are no longer behind an experimental flag in unstable and in future versions of Nix.

[srid]

utils will never need to be updated,

It needs to be updated if you want to use a new set of defaults for eachDefaultSystem. For example, https://github.com/numtide/treefmt/pull/162 updated it to get aarch64-darwin in the list (added in https://github.com/numtide/flake-utils/commit/997f7efcb746a9c140ce1f13c72263189225f482).

[voidus]

I definitely don't want to block this, but importing nixpkgs from the classic file makes stuff like inputs.easy-purescript.inputs.nixpkgs.follows = "nixpkgs"; impossible

[ursi]

I no longer have interest in this PR.