Hi all,
I haven't experienced functional programming very much, but now I'm
trying to learn Haskell and I've learned that: 1) in functional
programming LISTS are fundmental; 2) any "cycle" in FP become
recursion.
I also know that Python got some useful tool such as map, filter,
reduce... so I told: "let's try some FP-style programming with
Python!". I took a little example of Haskell:
listprimes :: Integer -> [Integer]
listprimes n = if n == 0 then sieve [2..] else sieve [2..(n-1)]
where
sieve [] = []
sieve (p:xs) = p : sieve (filter (\x -> mod x p > 0) xs)
and I tried to "translate" it in Python:
def sieve(s):
if s == []:
return []
else:
return [s[0]] + sieve(filter((lambda x: x % s[0] > 0),
s[1:]))
def listprimes(n):
return sieve(range(2,n))
These should be almost the same: listprimes actually lists prime
integers up to n-1. The result is: Haskell implementation works well,
maybe it's not the better way to do it, but it does what I wanted.
Python implementation gives me
RuntimeError: maximum recursion depth exceeded in cmp
My question is: how can we call a language "functional" if it's major
implementation has a limited stack? Or is my code wrong?
LS
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