[Haskell-beginners] Would you shed light on "undefined values" please?

Ertugrul Soeylemez 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)

More information about the Beginners mailing list