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

Paul Hudak paul.hudak at yale.edu
Sat Jun 24 14:54:04 EDT 2006

Stepan Golosunov wrote:
>>>>1:_|_ is certainly finite.
>>>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.
> What is "finite list" then?
> Is ones = 1:ones also finite?

Hmmm... never tried to write all this down in one place before, but I 
think this covers all cases:

A partial list is one that ends in _|_.
A total list is one that ends in [].
A finite list is either partial or total.
Any other list is infinite.

So "ones" is infinite.


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