Safe Haskell	Safe-Inferred
Language	Haskell2010

Distribution.Solver.Types.Progress

Synopsis

data Progress step fail done
- = Step step (Progress step fail done)
- | Fail fail
- | Done done
foldProgress :: (step -> a -> a) -> (fail -> a) -> (done -> a) -> Progress step fail done -> a

Documentation

data Progress step fail done Source #

A type to represent the unfolding of an expensive long running calculation that may fail. We may get intermediate steps before the final result which may be used to indicate progress and/or logging messages.

Constructors

Step step (Progress step fail done)
Fail fail
Done done

Instances

Instances details

Monoid fail => Alternative (Progress step fail) Source #
Instance details Defined in Distribution.Solver.Types.Progress Methods empty :: Progress step fail a # (<\|>) :: Progress step fail a -> Progress step fail a -> Progress step fail a # some :: Progress step fail a -> Progress step fail [a] # many :: Progress step fail a -> Progress step fail [a] #
Applicative (Progress step fail) Source #
Instance details Defined in Distribution.Solver.Types.Progress Methods pure :: a -> Progress step fail a # (<>) :: Progress step fail (a -> b) -> Progress step fail a -> Progress step fail b # liftA2 :: (a -> b -> c) -> Progress step fail a -> Progress step fail b -> Progress step fail c # (>) :: Progress step fail a -> Progress step fail b -> Progress step fail b # (<*) :: Progress step fail a -> Progress step fail b -> Progress step fail a #
Functor (Progress step fail) Source #
Instance details Defined in Distribution.Solver.Types.Progress Methods fmap :: (a -> b) -> Progress step fail a -> Progress step fail b # (<$) :: a -> Progress step fail b -> Progress step fail a #
Monad (Progress step fail) Source #
Instance details Defined in Distribution.Solver.Types.Progress Methods (>>=) :: Progress step fail a -> (a -> Progress step fail b) -> Progress step fail b # (>>) :: Progress step fail a -> Progress step fail b -> Progress step fail b # return :: a -> Progress step fail a #

foldProgress :: (step -> a -> a) -> (fail -> a) -> (done -> a) -> Progress step fail done -> a Source #

Consume a Progress calculation. Much like foldr for lists but with two base cases, one for a final result and one for failure.

Eg to convert into a simple Either result use:

foldProgress (flip const) Left Right