[Haskell-cafe] Newbie question on Haskell type
cgibbard at gmail.com
Fri Oct 14 03:17:12 EDT 2005
Right, forgot about seq there, but the point still holds that there
are a very limited number of functions of that type, and in
particular, the functions can't decide what to do based on the type
On 14 Oct 2005 05:49:27 -0000, voigt.16734551 at bloglines.com
<voigt.16734551 at bloglines.com> wrote:
> --- Cale Gibbard <cgibbard at gmail.com wrote:
> > As an example of this sort
> of thing, I know that there are only 4
> > values of type a -> Bool (without
> the class context). They are the
> > constant functions (\x -> True), (\x ->
> False), and two kinds of
> > failure (\x -> _|_), and _|_, where _|_ is pronounced
> "bottom" and
> > represents something along the lines of nontermination (aborting
> > program also counts).
> Not exactly. There are also (\x -> seq x True)
> and (\x -> seq x False), neither of which is equivalent to any of the four
> functions above.
> Janis Voigtlaender.
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