Safe Haskell	Trustworthy
Language	Haskell98

Data.Fold.Class

Synopsis

Documentation

class Choice p => Scan p where Source

Minimal complete definition

interspersing

Methods

prefix1 :: a -> p a b -> p a b Source

postfix1 :: p a b -> a -> p a b Source

run1 :: a -> p a b -> b Source

Apply a Folding to a single element of input

interspersing :: a -> p a b -> p a b Source

Instances

Scan L Source
Methods prefix1 :: a -> L a b -> L a b Source postfix1 :: L a b -> a -> L a b Source run1 :: a -> L a b -> b Source interspersing :: a -> L a b -> L a b Source
Scan L' Source
Methods prefix1 :: a -> L' a b -> L' a b Source postfix1 :: L' a b -> a -> L' a b Source run1 :: a -> L' a b -> b Source interspersing :: a -> L' a b -> L' a b Source
Scan L1 Source
Methods prefix1 :: a -> L1 a b -> L1 a b Source postfix1 :: L1 a b -> a -> L1 a b Source run1 :: a -> L1 a b -> b Source interspersing :: a -> L1 a b -> L1 a b Source
Scan L1' Source
Methods prefix1 :: a -> L1' a b -> L1' a b Source postfix1 :: L1' a b -> a -> L1' a b Source run1 :: a -> L1' a b -> b Source interspersing :: a -> L1' a b -> L1' a b Source
Scan M Source
Methods prefix1 :: a -> M a b -> M a b Source postfix1 :: M a b -> a -> M a b Source run1 :: a -> M a b -> b Source interspersing :: a -> M a b -> M a b Source
Scan M1 Source
Methods prefix1 :: a -> M1 a b -> M1 a b Source postfix1 :: M1 a b -> a -> M1 a b Source run1 :: a -> M1 a b -> b Source interspersing :: a -> M1 a b -> M1 a b Source
Scan R Source
Methods prefix1 :: a -> R a b -> R a b Source postfix1 :: R a b -> a -> R a b Source run1 :: a -> R a b -> b Source interspersing :: a -> R a b -> R a b Source
Scan R1 Source
Methods prefix1 :: a -> R1 a b -> R1 a b Source postfix1 :: R1 a b -> a -> R1 a b Source run1 :: a -> R1 a b -> b Source interspersing :: a -> R1 a b -> R1 a b Source

class Scan p => Folding p where Source

Minimal complete definition

prefixOf, postfixOf, runOf, filtering

Methods

prefix :: Foldable t => t a -> p a b -> p a b Source

Partially apply a Folding to some initial input on the left.

prefixOf :: Fold s a -> s -> p a b -> p a b Source

postfix :: Foldable t => p a b -> t a -> p a b Source

postfixOf :: Fold s a -> p a b -> s -> p a b Source

run :: Foldable t => t a -> p a b -> b Source

Apply a Folding to a container full of input:

>>> run ["hello","world"] $ L id (++) []
"helloworld"

>>> run [1,2,3] $ L id (+) 0
6

runOf :: Fold s a -> s -> p a b -> b Source

filtering :: (a -> Bool) -> p a b -> p a b Source

Instances

Folding L Source	efficient `prefix`, leaky `postfix`
Methods prefix :: Foldable t => t a -> L a b -> L a b Source prefixOf :: Fold s a -> s -> L a b -> L a b Source postfix :: Foldable t => L a b -> t a -> L a b Source postfixOf :: Fold s a -> L a b -> s -> L a b Source run :: Foldable t => t a -> L a b -> b Source runOf :: Fold s a -> s -> L a b -> b Source filtering :: (a -> Bool) -> L a b -> L a b Source
Folding L' Source	efficient `prefix`, leaky `postfix`
Methods prefix :: Foldable t => t a -> L' a b -> L' a b Source prefixOf :: Fold s a -> s -> L' a b -> L' a b Source postfix :: Foldable t => L' a b -> t a -> L' a b Source postfixOf :: Fold s a -> L' a b -> s -> L' a b Source run :: Foldable t => t a -> L' a b -> b Source runOf :: Fold s a -> s -> L' a b -> b Source filtering :: (a -> Bool) -> L' a b -> L' a b Source
Folding M Source	efficient `prefix`, efficient `postfix`
Methods prefix :: Foldable t => t a -> M a b -> M a b Source prefixOf :: Fold s a -> s -> M a b -> M a b Source postfix :: Foldable t => M a b -> t a -> M a b Source postfixOf :: Fold s a -> M a b -> s -> M a b Source run :: Foldable t => t a -> M a b -> b Source runOf :: Fold s a -> s -> M a b -> b Source filtering :: (a -> Bool) -> M a b -> M a b Source
Folding R Source	leaky `prefix`, efficient `postfix`
Methods prefix :: Foldable t => t a -> R a b -> R a b Source prefixOf :: Fold s a -> s -> R a b -> R a b Source postfix :: Foldable t => R a b -> t a -> R a b Source postfixOf :: Fold s a -> R a b -> s -> R a b Source run :: Foldable t => t a -> R a b -> b Source runOf :: Fold s a -> s -> R a b -> b Source filtering :: (a -> Bool) -> R a b -> R a b Source

beneath :: Profunctor p => Optic p Identity s t a b -> p a b -> p s t Source

Lift a Folding into a Prism.

This acts like a generalized notion of "costrength", when applied to a Folding, causing it to return the left-most value that fails to match the Prism, or the result of accumulating rewrapped in the Prism if everything matches.

>>> run [Left 1, Left 2, Left 3] $ beneath _Left $ R id (+) 0
Left 6

>>> run [Left 1, Right 2, Right 3] $ beneath _Left $ R id (+) 0
Right 2

beneath :: Prism s t a b -> p a b -> p s t
beneath :: Iso s t a b   -> p a b -> p s t