[Haskell-cafe] Re: Control.Exception.evaluate - 'correct
definition' not so correct
abhay.parvate at gmail.com
Thu May 8 02:16:16 EDT 2008
Thanks both for the the explanation and the link. The wikibook is really
On Wed, May 7, 2008 at 5:05 PM, apfelmus <apfelmus at quantentunnel.de> wrote:
> Abhay Parvate wrote:
> > Just for curiocity, is there a practically useful computation that uses
> > 'seq' in an essential manner, i.e. apart from the efficiency reasons?
> I don't think so because you can always replace seq with const id .
> In fact, doing so will get you "more" results, i.e. a computation that
> did not terminate may do so now.
> In other words, we have
> seq _|_ = _|_
> seq x = id for x > _|_
> (const id) _|_ = id
> (const id) x = id for x > _|_
> So, (const id) is always more defined (">") than seq .
> For more about _|_ and the semantic approximation order, see
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