Stability | experimental |
---|---|
Maintainer | conal@conal.net |
Unambiguous choice
For non-flat types (where values may be partially defined, rather than necessarily bottom or fully defined) and information merging, see the lub package, http://haskell.org/haskellwiki/Lub.
See unamb.cabal for the list of contributors.
- unamb :: a -> a -> a
- unamb' :: a -> a -> a
- unambs :: [a] -> a
- assuming :: Bool -> a -> a
- asAgree :: Eq a => a -> a -> a
- parCommute :: (a -> a -> b) -> a -> a -> b
- parCommuteShortCircuit :: (a -> a -> b) -> a -> a -> b
- parAnnihilator :: Eq a => (a -> a -> a) -> a -> a -> a -> a
- parIdentity :: Eq a => (a -> a -> a) -> a -> a -> a -> a
- parAnnihilatorIdentity :: Eq a => (a -> a -> a) -> a -> a -> a -> a -> a
- por :: Bool -> Bool -> Bool
- pand :: Bool -> Bool -> Bool
- pmin :: (Ord a, Bounded a) => a -> a -> a
- pmax :: (Ord a, Bounded a) => a -> a -> a
- pmult :: Num a => a -> a -> a
- amb :: a -> a -> IO a
- amb' :: a -> a -> IO a
- race :: IO a -> IO a -> IO a
- data BothBottom
Purely functional unambiguous choice
Unambiguous choice operator. Equivalent to the ambiguous choice
operator, but with arguments restricted to be equal where not bottom,
so that the choice doesn't matter. See also amb
.
If anything kills unamb while it is evaluating (like nested unambs), it can be retried later but, unlike most functions, work may be lost.
Some useful special applications of unamb
parCommute :: (a -> a -> b) -> a -> a -> bSource
Turn a binary commutative operation into one that tries both orders in
parallel. Useful when there are special cases that don't require
evaluating both arguments. For non-flat types and information merging,
see parCommute
in the lub
package.
parCommuteShortCircuit :: (a -> a -> b) -> a -> a -> bSource
Turn a binary commutative operation into one that may try both orders.
unlike parCommute, if one argument is already evaluated, the function is
tried *only* with that as its first argument and not in both orders. When
in doubt, use parCommute
.
parAnnihilator :: Eq a => (a -> a -> a) -> a -> a -> a -> aSource
parIdentity :: Eq a => (a -> a -> a) -> a -> a -> a -> aSource
parAnnihilatorIdentity :: Eq a => (a -> a -> a) -> a -> a -> a -> a -> aSource
pmin :: (Ord a, Bounded a) => a -> a -> aSource
Parallel min with minBound short-circuit and maxBound identity
pmax :: (Ord a, Bounded a) => a -> a -> aSource
Parallel max with maxBound short-circuit and minBound identity
Some related imperative tools
race :: IO a -> IO a -> IO aSource
Race two actions against each other in separate threads, and pick
whichever finishes first. See also amb
.
Exception thrown if neither value evaluates
data BothBottom Source
Use a particular exception as our representation for waiting forever.