[Haskell-cafe] Re: Functional progr., infinity, and the Universe

[Paul Hudak]

Stepan Golosunov wrote:
> On Fri, Jun 23, 2006 at 10:57:48AM -0400, Paul Hudak wrote:
> 
>>voigt.16734551 at bloglines.com wrote:
>>>I think quite
>>>a few people would agree that a finite list is one ending in []. So 1:_|_
>>>is a partial list, but not a finite one. 1:[] is a finite list.
>>
>>1:_|_ is certainly finite.  In what sense is it not?
> 
> And what is length _|_ ?

_|_, of course!! :-)

The point being, length is well-defined only for total lists; it is 
undefined for partial lists.  But this doesn't mean that a partial list 
isn't finite.

-Paul