| Safe Haskell | Safe-Inferred |
|---|---|
| Language | GHC2021 |
Fold.Effectful
Synopsis
- data EffectfulFold m a b = forall x.EffectfulFold {}
- run :: Foldable f => Monad m => EffectfulFold m a b -> f a -> m b
- effect :: Monad m => (a -> m b) -> EffectfulFold m a ()
- effectMonoid :: (Monoid w, Monad m) => (a -> m w) -> EffectfulFold m a w
- magma :: (a -> a -> a) -> Monad m => EffectfulFold m a (Maybe a)
- semigroup :: Semigroup a => Monad m => EffectfulFold m a (Maybe a)
- monoid :: Monoid a => Monad m => EffectfulFold m a a
- first :: Monad m => EffectfulFold m a (Maybe a)
- last :: Monad m => EffectfulFold m a (Maybe a)
- maximum :: Ord a => Monad m => EffectfulFold m a (Maybe a)
- minimum :: Ord a => Monad m => EffectfulFold m a (Maybe a)
- maximumBy :: (a -> a -> Ordering) -> Monad m => EffectfulFold m a (Maybe a)
- minimumBy :: (a -> a -> Ordering) -> Monad m => EffectfulFold m a (Maybe a)
- null :: Monad m => EffectfulFold m a Bool
- length :: Monad m => EffectfulFold m a Natural
- and :: Monad m => EffectfulFold m Bool Bool
- or :: Monad m => EffectfulFold m Bool Bool
- all :: Monad m => (a -> Bool) -> EffectfulFold m a Bool
- any :: Monad m => (a -> Bool) -> EffectfulFold m a Bool
- sum :: Num a => Monad m => EffectfulFold m a a
- product :: Num a => Monad m => EffectfulFold m a a
- mean :: Fractional a => Monad m => EffectfulFold m a a
- variance :: Fractional a => Monad m => EffectfulFold m a a
- standardDeviation :: Floating a => Monad m => EffectfulFold m a a
- element :: Eq a => Monad m => a -> EffectfulFold m a Bool
- notElement :: Eq a => Monad m => a -> EffectfulFold m a Bool
- find :: Monad m => (a -> Bool) -> EffectfulFold m a (Maybe a)
- lookup :: Eq a => Monad m => a -> EffectfulFold m (a, b) (Maybe b)
- index :: Monad m => Natural -> EffectfulFold m a (Maybe a)
- findIndex :: Monad m => (a -> Bool) -> EffectfulFold m a (Maybe Natural)
- elementIndex :: Eq a => Monad m => a -> EffectfulFold m a (Maybe Natural)
- list :: Monad m => EffectfulFold m a [a]
- reverseList :: Monad m => EffectfulFold m a [a]
- fold :: Monad m => Fold a b -> EffectfulFold m a b
- nonemptyFold :: Monad m => NonemptyFold a b -> EffectfulFold m a (Maybe b)
- shortcutFold :: Monad m => ShortcutFold a b -> EffectfulFold m a b
- shortcutNonemptyFold :: Monad m => ShortcutNonemptyFold a b -> EffectfulFold m a (Maybe b)
- hoist :: (forall x. m x -> n x) -> EffectfulFold m a b -> EffectfulFold n a b
- duplicate :: Applicative m => EffectfulFold m a b -> EffectfulFold m a (EffectfulFold m a b)
- premap :: Monad m => (a -> m b) -> EffectfulFold m b r -> EffectfulFold m a r
- prefilter :: Monad m => (a -> m Bool) -> EffectfulFold m a r -> EffectfulFold m a r
- drop :: Monad m => Natural -> EffectfulFold m a b -> EffectfulFold m a b
Type
data EffectfulFold m a b Source #
Processes inputs of type a and results in an effectful value of type m b
Constructors
| forall x. EffectfulFold | |
Instances
Run
run :: Foldable f => Monad m => EffectfulFold m a b -> f a -> m b Source #
Fold an listlike container to an action that produces a single summary result
Examples
General
effect :: Monad m => (a -> m b) -> EffectfulFold m a () Source #
Performs an action for each input, discarding the result
effectMonoid :: (Monoid w, Monad m) => (a -> m w) -> EffectfulFold m a w Source #
Performs an action for each input, monoidally combining the results from all the actions
magma :: (a -> a -> a) -> Monad m => EffectfulFold m a (Maybe a) Source #
Start with the first input, append each new input on the right with the given function
semigroup :: Semigroup a => Monad m => EffectfulFold m a (Maybe a) Source #
Append each new input on the right with (<>)
monoid :: Monoid a => Monad m => EffectfulFold m a a Source #
Start with mempty, append each input on the right with (<>)
Endpoints
Extrema
maximumBy :: (a -> a -> Ordering) -> Monad m => EffectfulFold m a (Maybe a) Source #
The greatest input with respect to the given comparison function
minimumBy :: (a -> a -> Ordering) -> Monad m => EffectfulFold m a (Maybe a) Source #
The least input with respect to the given comparison function
Length
Boolean
all :: Monad m => (a -> Bool) -> EffectfulFold m a Bool Source #
True if all inputs satisfy the predicate
any :: Monad m => (a -> Bool) -> EffectfulFold m a Bool Source #
True if any input satisfies the predicate
Numeric
mean :: Fractional a => Monad m => EffectfulFold m a a Source #
Numerically stable arithmetic mean of the inputs
variance :: Fractional a => Monad m => EffectfulFold m a a Source #
Numerically stable (population) variance over the inputs
standardDeviation :: Floating a => Monad m => EffectfulFold m a a Source #
Numerically stable (population) standard deviation over the inputs
Search
element :: Eq a => Monad m => a -> EffectfulFold m a Bool Source #
True if any input is equal to the given value
notElement :: Eq a => Monad m => a -> EffectfulFold m a Bool Source #
False if any input is equal to the given value
find :: Monad m => (a -> Bool) -> EffectfulFold m a (Maybe a) Source #
The first input that satisfies the predicate, if any
lookup :: Eq a => Monad m => a -> EffectfulFold m (a, b) (Maybe b) Source #
The b from the first tuple where a equals the given value, if any
Index
index :: Monad m => Natural -> EffectfulFold m a (Maybe a) Source #
The nth input, where n=0 is the first input, if the index is in bounds
findIndex :: Monad m => (a -> Bool) -> EffectfulFold m a (Maybe Natural) Source #
The index of the first input that satisfies the predicate, if any
elementIndex :: Eq a => Monad m => a -> EffectfulFold m a (Maybe Natural) Source #
The index of the first input that matches the given value, if any
List
list :: Monad m => EffectfulFold m a [a] Source #
All the inputs
reverseList :: Monad m => EffectfulFold m a [a] Source #
All the inputs in reverse order
Conversion
fold :: Monad m => Fold a b -> EffectfulFold m a b Source #
Generalize a pure fold to an effectful fold
nonemptyFold :: Monad m => NonemptyFold a b -> EffectfulFold m a (Maybe b) Source #
Turn a nonempty fold that requires at least one input into a fold that
returns Nothing when there are no inputs
shortcutFold :: Monad m => ShortcutFold a b -> EffectfulFold m a b Source #
shortcutNonemptyFold :: Monad m => ShortcutNonemptyFold a b -> EffectfulFold m a (Maybe b) Source #
Utilities
hoist :: (forall x. m x -> n x) -> EffectfulFold m a b -> EffectfulFold n a b Source #
Shift an effectful fold from one monad to another with a morphism such as
lift or liftIO
duplicate :: Applicative m => EffectfulFold m a b -> EffectfulFold m a (EffectfulFold m a b) Source #
Allows to continue feeding an effectful fold even after passing it to a function that closes it
premap :: Monad m => (a -> m b) -> EffectfulFold m b r -> EffectfulFold m a r Source #
Apply a function to each input
prefilter :: Monad m => (a -> m Bool) -> EffectfulFold m a r -> EffectfulFold m a r Source #
Consider only inputs that match an effectful predicate
drop :: Monad m => Natural -> EffectfulFold m a b -> EffectfulFold m a b Source #
Ignore the first n inputs