Haxl.Core.Parallel

Psuedo-parallel operations. Most users should import Haxl.Core instead.

Parallel operations

biselect :: GenHaxl u w (Either a b) -> GenHaxl u w (Either a c) -> GenHaxl u w (Either a (b, c))

pAnd :: GenHaxl u w Bool -> GenHaxl u w Bool -> GenHaxl u w Bool infixr 5

Parallel version of '(.&&)'. Both arguments are evaluated in parallel, and if either returns False then the other is not evaluated any further.

WARNING: exceptions may be unpredictable when using pAnd. If one argument returns False before the other completes, then pAnd returns False immediately, ignoring a possible exception that the other argument may have produced if it had been allowed to complete.

pOr :: GenHaxl u w Bool -> GenHaxl u w Bool -> GenHaxl u w Bool infixr 4

Parallel version of '(.||)'. Both arguments are evaluated in parallel, and if either returns True then the other is not evaluated any further.

WARNING: exceptions may be unpredictable when using pOr. If one argument returns True before the other completes, then pOr returns True immediately, ignoring a possible exception that the other argument may have produced if it had been allowed to complete.

unsafeChooseFirst :: GenHaxl u w a -> GenHaxl u w b -> GenHaxl u w (Either a b)

This function takes two haxl computations as input, and returns the output of whichever computation finished first. This is clearly non-deterministic in its output and exception behavior, be careful when using it.