Data.The

Documentation

class The d a | d -> a where

A class for extracing "the" underlying value. the should ideally be a coercion from some newtype wrap of a back to a.

For this common use case, in the module where newtype New a = New a is defined, an instance of The can be created with an empty definition:

newtype New a = New a
instance The (New a) a

Methods

the :: d -> a

the :: Coercible d a => d -> a

Instances

The (Named name a) a

Methods

the :: Named name a -> a

The (Satisfies p a) a

Methods

the :: Satisfies p a -> a

The a' a => The ((:::) a' p) a

Methods

the :: (a' ::: p) -> a

pattern The :: The d a => a -> d

A view pattern for discarding the wrapper around a value.

f (The x) = expression x

is equivalent to

f x = let x' = the x in expression x'