Generics.Instant.Functions.Empty

Generically produce a single finite value of a datatype.

Documentation

class Empty a where

Methods

empty' :: a

Instances

Empty Bool

Empty Char

Empty Double

Empty Float

Empty Int

Empty Integer

Empty U

Empty a => Empty [a]

Empty a => Empty (Maybe a)

Empty a => Empty (Rec a)

Empty a => Empty (Var a)

(Empty a, Empty b) => Empty (a, b)

Empty a => Empty (C c a)

(Empty a, Empty b) => Empty (:*: a b)

(HasRec a, Empty a, Empty b) => Empty (:+: a b)

empty :: (Representable a, Empty (Rep a)) => a

class HasRec a where

We use HasRec to check for recursion in the structure. This is used to avoid selecting a recursive branch in the sum case for Empty.

Methods

hasRec' :: a -> Bool

Instances

HasRec Char

HasRec Double

HasRec Float

HasRec Int

HasRec Integer

HasRec U

HasRec (Rec a)

HasRec (Var a)

HasRec a => HasRec (C c a)

(HasRec a, HasRec b) => HasRec (:*: a b)

(HasRec a, HasRec b) => HasRec (:+: a b)