newtype | data

Mark Carroll mark@chaos.x-philes.com
Fri, 5 Oct 2001 16:30:32 -0400 (EDT)


On 5 Oct 2001, Marcin 'Qrczak' Kowalczyk wrote:
(snip)
> It could indeed be represented in the same way, but they behave
> differently in pattern matching: case undefined of T _ -> ()
> is () in the case of newtype and undefined in the case of strict data.

Ah. I don't really use "error" or anything in code that may not need to be
evaluated, which is why I didn't think of (or care (-:) about that! I'm
assuming that other people do!

It's like Lisp, I guess - I rarely used eval, but everyone else seemed to.

-- Mark