fold
Fold
f/y
x f/y
x f/y
Fold, also known as reduce, foldl and over, takes a dyadic function f
and reduces an array y
using it.
Fold is a very strong utility. For example, you can sum a list using +/
.
+/1 2 3 4 10 ,/("ab";1;`d`a`b) ("a" "b" 1 `d `a `b)
Specifying a left argument x
uses it as an initial value.
3 +/1 2 3 4 13