[Haskell-cafe] Re: Web server continued
barsoap at web.de
Mon Dec 31 14:33:12 EST 2007
Jonathan Cast <jonathanccast at fastmail.fm> wrote:
> On 31 Dec 2007, at 10:43 AM, Achim Schneider wrote:
> > Achim Schneider <barsoap at web.de> wrote:
> >> That's not specified though, the runtime could choose to let +
> >> force the two chunks the different way round.
> > And that is probably also the reason why [1..] == [1..] is _|_.
> > Is "Something that can be, in any evaluation strategy, be bottom, is
> > bottom" quite right, i.e. the formalism defined such, that no
> > possibly unevaluable thing is defined?
> No. Again, the semantics of Haskell are defined denotationally, not
> operationally. In fact, Haskell implementations are required to use
> an evaluation strategy that finds a value whenever one
> (denotationally) exists, so it's the exact opposite of what you said.
> Strict languages come much closer to your rule, OTOH.
I guess I just have to change unevaluable to not denotationally
reducable. Except to _|_, of course. Which makes it completely logical,
but also completely meaningless if you don't look at the algebra.
It seems like I have to translate the formulae to plain English after
Not today, though, I'm planning to be drunk in one hour and a half.
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