On Jan 22, 2007, at 6:57 AM, Simon Peyton-Jones wrote:

I'm thinking of implementing it in GHC, so I'd be interested in feedback of the form - how desirable is it to have a feature of this general form?

While it looks like a useful extension with a lot of bang for the buck, I think I'd prefer to live without it; two reasons: 1) I'm a minimalist 2) I find that using my pattern combinators (http://citeseer.ist.psu.edu/tullsen00first.html) and do-notation I get by very well without using any of the advanced features of patterns. OK, I guess I'm a little biased.

- can this particular proposal be improved?

I definitely agree with Claus's comment:

5 possible extension 1 smells of superfluous complexity. There is almost no gain compared to using tuples, but there's a lot to pay in added types and rules.m