On Nov 23, 7:05 pm, greg <[EMAIL PROTECTED]> wrote:
> My feeling is that Python shouldn't provide a bunch of
> different versions of the same function that differ only in
> the degree of currying. If you want a particular curried
> combination, it's easy enough to create it as needed using
> lambda, nested functions or partial().
I agree about noy having different functions with different levels of
currying.
What's interesting is that no-one has yet implemented a real foldr on
this thread -- all of the examples have been of foldl. The foldr is
right-associative. This doesn't matter for non-associative functions
like "+", but it does for associative functions like "-".
def foldl(f, l, i): # same as reduce()
if len(l) == 0:
return i
else:
return foldl(f, l[1:], f(i, l[0]))
def foldr(f, l, i):
l.reverse()
def _foldr(f, l, i):
if len(l) == 0:
return i
else:
return _foldr(f, l[1:], f(l[0], i))
return _foldr(f, l, i)
foldl(int.__sub__, [1,2,3,4], 0)
# -10
foldr(int.__sub__, [1,2,3,4], 0)
# -2
Regards,
Jordan
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