[Haskell-cafe] Re: Where do I put the seq?

Ketil Malde ketil at malde.org
Thu Aug 20 14:02:38 EDT 2009


David Leimbach <leimy2k at gmail.com> writes:

> I'm pretty certain that forcing a pattern match via case is what disallows
> the laziness to get out of hand.  The case statement, when evaluated, must
> choose a matched pattern branch, even if it's the only possibility, which
> ends up boiling down to "seq" anyway doesn't it?

    Prelude> case undefined of x -> ()
    ()

So I think you are incorrect: the 'undefined' here isn't evaluated by
the case. 

-k
-- 
If I haven't seen further, it is by standing in the footprints of giants


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