[Haskell-cafe] Python is lazier than Haskell

[Jerzy Karczmarczuk]

Alexander Solla comments my comment :
>
>
>     Alright, my turn. I never wanted to write non-terminating programs
>     (what for?),
>
>
> Daemons/servers/console interfaces/streaming clients?
Come on, not THIS kind of non-termination. This has little to do with 
strictness/laziness, I think. Endless loops can be coded in various ways...
>
>     I see ONE usage of laziness: the possibility to write co-recursive
>     equations, which become algorithms
>
>
> What about "infinite" lists?  There is no need for mutually recursive 
> functions to see the usefulness of a list which never ends, and is 
> computed to the length that your algorithm /acutally/ requires.
>
This is almost EXACTLY what I meant. When I say "co-recursive", I do not 
mean "mutually recursive". Rather the extrapolating recursion, not 
necessarily "terminating" (lacking the base clause) but finitely 
progressing, such as the standard definition of the stream of integers, 
used to scare the beginners...

ints = 1 : zipWith (+)  (fix (1:)) ints
   where  fix f = f (fix f)

Thanks.

Jerzy Karczmarczuk

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