| Copyright | (c) Conal Elliott 2008 |
|---|---|
| License | BSD3 |
| Maintainer | conal@conal.net |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell98 |
Data.Unamb
Contents
Description
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 :: (Eq a, 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.
unamb' :: a -> a -> a Source #
For use when we already know that neither argument is already evaluated
Some useful special applications of unamb
parCommute :: (a -> a -> b) -> a -> a -> b Source #
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 -> b Source #
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 -> a Source #
parIdentity :: Eq a => (a -> a -> a) -> a -> a -> a -> a Source #
parAnnihilatorIdentity :: Eq a => (a -> a -> a) -> a -> a -> a -> a -> a Source #
pmin :: (Ord a, Bounded a) => a -> a -> a Source #
Parallel min with minBound short-circuit and maxBound identity
pmax :: (Ord a, Bounded a) => a -> a -> a Source #
Parallel max with maxBound short-circuit and minBound identity
pmult :: (Eq a, Num a) => a -> a -> a Source #
Parallel multiplication with 0 short-circuit, and 1 identity
Some related imperative tools
amb' :: a -> a -> IO a Source #
For use when we already know that neither argument is already evaluated
race :: IO a -> IO a -> IO a Source #
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.
Instances