The other uses I've found for it besides + and * were with and and or, but now we have any
and all
to replace those cases.
foldl
and foldr
do come up in Scheme a lot...
Here's some cute usages:
Flatten a list
Goal: turn [[1, 2, 3], [4, 5], [6, 7, 8]]
into [1, 2, 3, 4, 5, 6, 7, 8]
.
reduce(list.__add__, [[1, 2, 3], [4, 5], [6, 7, 8]], [])
List of digits to a number
Goal: turn [1, 2, 3, 4, 5, 6, 7, 8]
into 12345678
.
Ugly, slow way:
int("".join(map(str, [1,2,3,4,5,6,7,8])))
Pretty reduce
way:
reduce(lambda a,d: 10*a+d, [1,2,3,4,5,6,7,8], 0)