Test.IOSpec.Types

This module contains the basic data types underlying the IOSpec library. Most of the types and classes in this module are described in http://www.cs.nott.ac.uk/~wss/Publications/DataTypesALaCarte.pdf.

The IOSpec type.

data IOSpec f a

A value of type IOSpec f a is either a pure value of type a or some effect, determined by f. Crucially, IOSpec f is a monad, provided f is a functor.

Constructors

Pure a

Impure (f (IOSpec f a))

Instances

Functor f => Monad (IOSpec f)

Functor f => Functor (IOSpec f)

foldIOSpec :: Functor f => (a -> b) -> (f b -> b) -> IOSpec f a -> b

The fold over IOSpec values.

Coproducts of functors

data (f :+: g) x

The coproduct of functors

Constructors

Inl (f x)

Inr (g x)

Instances

(:<: f g, Functor f, Functor g, Functor h) => f :<: (:+: h g)

(Functor f, Functor g) => f :<: (:+: f g)

(Functor f, Functor g) => Functor (:+: f g)

(Executable f, Executable g) => Executable (:+: f g)

Injections from one functor to another

class (Functor sub, Functor sup) => sub :<: sup

The (:<:) class

Instances

Functor f => f :<: f

(:<: f g, Functor f, Functor g, Functor h) => f :<: (:+: h g)

(Functor f, Functor g) => f :<: (:+: f g)

inject :: g :<: f => g (IOSpec f a) -> IOSpec f a