Pipes.Interleave

Documentation

interleave

Arguments

:: (Monad m, Ord a)

=> [Producer a m ()]

element producers

-> Producer a m ()

Interleave elements from a set of Producers such that the interleaved stream is increasing with respect to the given ordering.

>>> toList $ interleave [each [1,3..10], each [1,5..20]]
[1,1,3,5,5,7,9,9,13,17]

combine

Arguments

:: (Monad m, Eq a)

=> (a -> a -> a)

combine operation

-> Producer a m r

-> Producer a m r

Given a stream of increasing elements, combine those that are equal.

>>> let append (Entry k v) (Entry _ v') = Entry k (v+v')
>>> toList $ combine append (each $ map (uncurry Entry) [(1,1), (1,4), (2,3), (3,10)])
[Entry {priority = 1, payload = 5},Entry {priority = 2, payload = 3},Entry {priority = 3, payload = 10}]

combineM

Arguments

:: (Monad m, Eq a)

=> (a -> a -> m a)

combine operation

-> Producer a m r

-> Producer a m r

combine with monadic side-effects in the combine operation.

merge

Arguments

:: (Monad m, Ord a)

=> (a -> a -> a)

combine operation

-> [Producer a m ()]

producers of elements

-> Producer a m ()

Equivalent to combine composed with interleave

>>> let append (Entry k v) (Entry _ v') = Entry k (v+v')
>>> let producers = [ each [Entry i 2 | i <- [1,3..10]], each [Entry i 10 | i <- [1,5..20]] ] :: [Producer (Entry Int Int) Identity ()]
>>> toList $ merge append producers
[(1,12),(3,2),(5,12),(7,2),(9,12),(13,10),(17,10)]

mergeM

Arguments

:: (Monad m, Ord a)

=> (a -> a -> m a)

combine operation

-> [Producer a m ()]

producers of elements

-> Producer a m ()

Merge with monadic side-effects in the combine operation.

groupBy :: forall a r m. (Monad m, Ord a) => Producer a m r -> Producer [a] m r

Split stream into groups of equal elements. Note that this is a non-local operation: if the Producer generates a large run of equal elements, all of them will remain in memory until the run ends.

>>> toList $ groupBy (each [Entry 1 1, Entry 1 4, Entry 2 3, Entry 3 10])
[[Entry {priority = 1, payload = 1},Entry {priority = 1, payload = 4}],[Entry {priority = 2, payload = 3}],[Entry {priority = 3, payload = 10}]]