[Haskell-cafe] Order of Evaluation

PR Stanley prstanley at ntlworld.com
Fri May 9 13:52:55 EDT 2008


Hi
  (take 4 . map (>0)) (f s t)
  where
	s = 2 : t
	t = 3 : s
  f = zipWith (-)
What would be the order of evaluation for the above code? How would I 
illustrate the evaluation step-by-step?
I'm guessing that  the code necessitates lazy evaluation and as such 
it starts with take then it applies f which in turn applies s and t 
and zipWith until the first element satisfies the predicate in map 
and This is repeated 4 times
What does the list think?
Many thanks,
Paul
P.S. I'm not done with induction. I'm just letting it rst for a bit.



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