Data.Scannable

class Scannable f  where

The Scannable class provides scanl and scanr functions for structures that are not Traversable.

Instances should also satisfy the following laws

If it is also a Foldable then it should preserve length:

• length (scanl f init fa) == length fa
• length (scanr (flip f) init fa) == length fa

If it is also a Functor then it behaves like map if the accumulated argument is ignored:

• scanl (\_ → f) _ fa == map f fa
• scanr (\a _ → f a) _ fa == map f fa

Members

• scanl :: forall b a. (b -> a -> b) -> b -> f a -> f b
• scanr :: forall b a. (a -> b -> b) -> b -> f a -> f b

Instances

• Scannable Maybe
• Scannable Array
• Scannable Additive
• Scannable Multiplicative
• Scannable Disj
• Scannable Conj
• Scannable Dual
• Scannable Last
• Scannable First

scannablePreservesLength :: forall b a f. Foldable f => Scannable f => (b -> a -> b) -> b -> f a -> Boolean

scannableMapping :: forall b a f. Eq (f b) => Functor f => Scannable f => (a -> b) -> b -> f a -> Boolean

verifyScannable :: forall b a f. Eq (f b) => Functor f => Foldable f => Scannable f => (b -> a -> b) -> (a -> b) -> b -> f a -> Boolean

defaultScanl :: forall f b a. ((a -> b -> b) -> b -> f a -> f b) -> (b -> a -> b) -> b -> f a -> f b

defaultScanr :: forall f b a. ((b -> a -> b) -> b -> f a -> f b) -> (a -> b -> b) -> b -> f a -> f b