Returns the reduction of the realized elements of coll
using function f. Note f will not necessarily be called
consecutively, and so must be commutative. Also note that
(f base an-element) might be performed many times, i.e. base is not
an initial value as with sequential reduce.
(defn preduce
"Returns the reduction of the realized elements of coll
using function f. Note f will not necessarily be called
consecutively, and so must be commutative. Also note that
(f base an-element) might be performed many times, i.e. base is not
an initial value as with sequential reduce."
[f base coll]
(. (par coll) (reduce (reducer f) base)))
