Data.Digit.D2

Documentation

class D2 d where

Minimal complete definition

d2

Methods

d2 :: Prism' d ()

x2 :: d

Instances

D2 ()

Methods

d2 :: Prism' () ()

x2 :: ()

D2 a => D2 (Digit2 a)

Methods

d2 :: Prism' (Digit2 a) ()

x2 :: Digit2 a

D2 d => D2 (Either d x)

Methods

d2 :: Prism' (Either d x) ()

x2 :: Either d x

parse2 :: (D2 d, CharParsing p) => p d

>>> parse (parse2 <* eof) "test" "2" :: Either ParseError (Digit2 ())
Right (Digit2 ())

>>> parse parse2 "test" "2xyz" :: Either ParseError (Digit2 ())
Right (Digit2 ())

>>> isn't _Right (parse parse2 "test" "xyz" :: Either ParseError (Digit2 ()))
True

\c -> c /= '2' ==> isn't _Right (parse parse2 "test" [c] :: Either ParseError (Digit2 ()))