[Nix-dev] haskell structure for all of nixpkgs

[stewart mackenzie]

Hi Tomasz,

On Sun, Apr 24, 2016 at 6:12 PM, Tomasz Czyż <tomasz.czyz at gmail.com> wrote:
> do you have any description of what you are exactly talking about?

Adopting this approach brings a huge amount of flexibility, could be
that this style of structuring can be rolled out for different
languages. Sure there are differences in how languages publish
packages, but it could be Peter's solution is a 80% solution
applicable to most languages.

This approach might mean if nixers want support for a new language
they could plug into this this rather advanced packaging structure and
hopefully it works out well. Existing supported languages on Nix could
start converging onto this style of packaging.

The current setup is each language has their own ad hoc solution for
getting packages, these packages are tightly bound.
So in the current setup, callPackage refers to a specific file,
whereas in the haskell setup the callPackage refers to a specific
recursive set of expressions that are self contained.
The package set is a function which produces a package set. This
function takes an argument which produces a package set it should
produce. It's better to let Peter describe it:
https://youtu.be/TDnZsBxqeBM?list=PL_IxoDz1Nq2Y7mIxMZ28mVtjRbbnlVdmy&t=1850

(I think) Rok Garbas, has a good question at the end!

Anyway, I just wanted to raise this subject / see if this is an issue
people are interested in.