[Haskell-beginners] Would you shed light on "undefined values" please?
es at ertes.de
Mon Jun 27 18:40:32 CEST 2011
Brent Yorgey <byorgey at seas.upenn.edu> wrote:
> > Bottom arises, as soon as a language is total. This is related to
> > the halting problem. Bottom is the value, which is never computed
> > in the sense that it never results. Only nontotal languages (like
> > Agda) can prevent bottom values from appearing.
> That is a funny use of the word "total"; I think you mean
> "Turing-complete". "Total" is usually used of languages in which it
> is only possible to define total functions -- such as Agda. Haskell
> is non-total since it is possible to define non-total, i.e. partial,
> functions, which are undefined for some inputs.
Indeed, i flipped the meanings. =)
nightmare = unsafePerformIO (getWrongWife >>= sex)
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