Safe Haskell	None
Language	Haskell2010

Control.Lens.Format

Synopsis

data Format a b = Format {
- getMaybe :: a -> Maybe b
- reverseGet :: b -> a
}
normalize :: Format a b -> a -> Maybe a
composePrism :: Format a b -> Prism' b c -> Format a c
composeIso :: Format a b -> Iso' b c -> Format a c
fromPrism :: Prism' a b -> Format a b
fromIso :: Iso' a b -> Format a b

Documentation

data Format a b Source #

A normalizing optic, isomorphic to Prism but with different laws, specifically getMaybe needs not to be injective; i.e., distinct inputs may have the same getMaybe result, which combined with a subsequent reverseGet yields a normalized form for a. Composition with stronger optics (Prism and Iso) yields another Format.

Constructors

Format
Fields getMaybe :: a -> Maybe b reverseGet :: b -> a

Instances

Invariant (Format a) Source #
Instance details Defined in Control.Lens.Format Methods invmap :: (a0 -> b) -> (b -> a0) -> Format a a0 -> Format a b #

normalize :: Format a b -> a -> Maybe a Source #

getMaybe and reverseGet, yielding a normalized formatted value. Subsequent getMaybe/reverseGet cycles are idempotent.

composePrism :: Format a b -> Prism' b c -> Format a c Source #

Compose with a Prism.

composeIso :: Format a b -> Iso' b c -> Format a c Source #

Compose with an Iso.

fromPrism :: Prism' a b -> Format a b Source #

A Prism is trivially a Format.

fromIso :: Iso' a b -> Format a b Source #

An Isomorphism is trivially a Format.