A pmap implementation in Racket inspired from Clojure's pmap.

Map applies a funcion to an item one at a time, pmapf constructs a future for every item thats then run in parallel. pmapp constructs a place for every item thats then run in parallel.

For heavyer computations the gain is positive, because of the future/place overhead simpler computations will run wors in pmapf/pmapp than in map.

With the help of CarlSmotricz and the racket mailing list! :-)