[Haskell-cafe] Minimal Haskell Platform

[Simon Hengel]

> >and I have a somewhat cunning plan along these lines (related to some
> >other ghc-pkg/cabal improvement work) which might make that rather
> >easier
> >
> >what I want is for ghc itself to come with multiple profiles, with one
> >being the minimum (base + rts + deps), and that could be used as a basis
> >for new envs
> 
> With such a feature, it sounds like we can get the best of both worlds:
> * a feature-rich Haskell Platform to support beginners
> * minimal sandboxes for advanced users

The issue with such integrated approaches that affect the whole
toolchain (ghc, cabal, etc.) is that this can seriously harm innovation,
at least if the net result is that it gets harder and harder to write
alternative package managers, etc.

TL;DR: If anything, we should make things *less integrated* (read more
open and hackable).

Let me try to make my point by looking at Haddock.  Let's assume you are
not happy with the current state of Haskell documentation tools.  In
such a situation it can makes perfect sense to give it a fresh start.
But Haddock is so integrated with GHC, Hackage, Cabal,...  that this is
very hard to do.  You can write an alternate documentation tool, but it
may be hard for potential uses to experiment with it.  Currently I think
the only feasible way to get your changes in or experiment with new
ideas is through the current maintainer, and if the current maintainer
thinks your approach is a bad idea or just does not like you or does not
have the time to look at your code you may be in a situation where it's
hard to improve things.  There is a lack of competition and I think it
is not something absurd to assume that this lack of competition results
in a lack of innovation.

> >Where would something like the HP actually make sense?  For stuff that
> >has external dependencies that are not easily  installable with
> >cabal-install (like curses bindings, SSL support, etc.).  We have none
> >of this in the HP.  So I think currently we just have additional costs,
> >but no benefits (+ we harm innovation by arbitrarily "endorsing" random
> >packages).
> 
> I understand this point of view, but allow me to offer an opposing one.
> By putting packages with external dependencies into Haskell Platform, we
> often increase the dependencies of Haskell Platform itself.  For example,
> Haskell Platform currently includes Graphics packages; installing Haskell
> Platform on a server entails installing a number of OpenGL libraries that
> are never used.

My point here was that (from my perspective) the cost/benefit ratio of
bundling packages that are easily installable with cabal-install is
negative.

Cheers,
Simon