[Haskell-cafe] Re: [Haskell] View patterns in GHC: Request for feedback

apfelmus apfelmus at quantentunnel.de
Tue Jul 24 17:07:28 EDT 2007

Simon Peyton-Jones wrote:
> Views have been the subject of rather inconclusive debate for a long time,
> certainly since the inception of Haskell. I'm thinking of pattern
views as a way
> to break the logjam by implementing something that is a reasonable stab,
> and seeing whether it "sticks". I thought of pattern guards in the
same way,
> and they certainly seem to have stuck. But we can only find out by
trying it out.

What I fear the most is exactly that this proposal "sticks" and becomes
the de-facto standard :(

IMHO, the long-time debate about views is not whether they're useful (I
think they are!) but which concrete form to choose. Unfortunately, all
of the proposals so far are somehow like Dr. Jekyll and Mr. Hyde: one
side is nice but the other is rather ugly.

In the end, I might end up using the currently proposed pattern views,
not because I'm fond of the proposal but simply because they're
implemented and the pain of not using views is too big.


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