Set package:protolude
x `setBit` i is the same as x .|. bit i
Set the number of Haskell threads that can run truly simultaneously
(on separate physical processors) at any given time. The number passed
to
forkOn is interpreted modulo this value. The initial value
is given by the
+RTS -N runtime flag.
This is also the number of threads that will participate in parallel
garbage collection. It is strongly recommended that the number of
capabilities is not set larger than the number of physical processor
cores, and it may often be beneficial to leave one or more cores free
to avoid contention with other processes in the machine.