[Haskell-cafe] Re: Order of evaluation
apfelmus at quantentunnel.de
Thu Jul 26 12:18:52 EDT 2007
Jon Harrop wrote:
> If you have a boolean-or expression:
> a || b
> will "a" be evaluated before "b" in Haskell as it is in other languages?
Yes, although the meaning of the phrase "evaluated before" is a bit
tricky in a lazy language, so it's probably better to state it with
denotational semantics alone:
_|_ || b = _|_
Maybe you also want to know whether the second argument "is evaluated".
This is answered by
True || _|_ = True
False || _|_ = _|_
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