Safe Haskell | None |
---|---|
Language | Haskell98 |
Deprecated: This structure does not perform well, and will be removed in future versions
This module defines the AList
type, a list that supports
constant-time append, and is therefore ideal for building the
result of tree-shaped parallel computations.
- data AList a
- empty :: AList a
- singleton :: a -> AList a
- cons :: a -> AList a -> AList a
- head :: AList a -> a
- tail :: AList a -> AList a
- length :: AList a -> Int
- null :: AList a -> Bool
- append :: AList a -> AList a -> AList a
- toList :: AList a -> [a]
- fromList :: [a] -> AList a
- fromListBalanced :: [a] -> AList a
- filter :: (a -> Bool) -> AList a -> AList a
- map :: (a -> b) -> AList a -> AList b
- partition :: (a -> Bool) -> AList a -> (AList a, AList a)
- parBuildThresh :: (NFData a, ParFuture f p) => Int -> InclusiveRange -> (Int -> a) -> p (AList a)
- parBuildThreshM :: (NFData a, ParFuture f p) => Int -> InclusiveRange -> (Int -> p a) -> p (AList a)
- parBuild :: (NFData a, ParFuture f p) => InclusiveRange -> (Int -> a) -> p (AList a)
- parBuildM :: (NFData a, ParFuture f p) => InclusiveRange -> (Int -> p a) -> p (AList a)
- depth :: AList a -> Int
- balance :: AList a -> AList a
The AList
type and operations
List that support constant-time append (sometimes called join-lists).
O(n) take the head element of an AList
NB. linear-time, because the list might look like this:
(((... `append` a) `append` b) `append` c)
fromListBalanced :: [a] -> AList a #
Regular (non-parallel) Combinators
Operations to build AList
s in the Par
monad
parBuildThresh :: (NFData a, ParFuture f p) => Int -> InclusiveRange -> (Int -> a) -> p (AList a) #
A parMap over an AList can result in more balanced parallelism than the default parMap over Traversable data types. parMap :: NFData b => (a -> b) -> AList a -> Par (AList b)
Build a balanced AList
in parallel, constructing each element as a
function of its index. The threshold argument provides control
over the degree of parallelism. It indicates under what number
of elements the build process should switch from parallel to
serial.
parBuildThreshM :: (NFData a, ParFuture f p) => Int -> InclusiveRange -> (Int -> p a) -> p (AList a) #
Variant of parBuildThresh
in which the element-construction function is itself a Par
computation.
parBuild :: (NFData a, ParFuture f p) => InclusiveRange -> (Int -> a) -> p (AList a) #
"Auto-partitioning" version of parBuildThresh
that chooses the threshold based on
the size of the range and the number of processors..
parBuildM :: (NFData a, ParFuture f p) => InclusiveRange -> (Int -> p a) -> p (AList a) #
like parBuild
, but the construction function is monadic