loop package:massiv

Efficient loop with an accumulator

Applicative loop. Use monadic loopM when possible, since it will be more efficient.

Efficient Applicative loop. Result of each iteration is discarded.

loopA_ initial cond incr f === loopA initial cond incr (pure ()) (\i -> id <$ f i)

Similar to loopM, but way less efficient monadic loop with an accumulator that reverses the direction of action application. eg:

>>> loopDeepM 1 (< 20) (+ 2) [] (\i a -> Just (i:a))
Just [1,3,5,7,9,11,13,15,17,19]

Equivalent to:

>>> loopM 19 (>= 1) (subtract 2) [] (\i a -> Just (i:a))
Just [1,3,5,7,9,11,13,15,17,19]

Efficient monadic loop with an accumulator

>>> loopM 1 (< 20) (+ 2) [] (\i a -> Just (i:a))
Just [19,17,15,13,11,9,7,5,3,1]

Deprecated: In favor of loopA_

Similar to loopM_ except the action accepts not only the value for current step, but also for the next one as well.

Similar to loopM_ except the action accepts not only the value for current step, but also for the next one as well.

Efficient monadic loop with extra linear index incremented by 1.

>>> iloopA_ 100 1 (< 10) (+ 2) (\i ix -> print (i, ix))
(100,1)
(101,3)
(102,5)
(103,7)
(104,9)

Efficient monadic loop with an accumulator and extra linear index incremented by 1.

>>> iloopM 100 1 (< 20) (+ 2) [] (\i ix a -> Just ((i, ix) : a))
Just [(109,19),(108,17),(107,15),(106,13),(105,11),(104,9),(103,7),(102,5),(101,3),(100,1)]