Safe Haskell	None
Language	Haskell2010

Control.Monad.Foil.Relative

Synopsis

class RelMonad (f :: S -> Type) (m :: S -> Type) where
- rreturn :: forall (a :: S). f a -> m a
- rbind :: forall (b :: S) (a :: S). Distinct b => Scope b -> m a -> (f a -> m b) -> m b
liftRM :: forall f m (b :: S) (a :: S). (RelMonad f m, Distinct b) => Scope b -> (f a -> f b) -> m a -> m b

Documentation

class RelMonad (f :: S -> Type) (m :: S -> Type) where Source #

Relative monads, restricted to types indexed by scopes in kind S.

Methods

rreturn :: forall (a :: S). f a -> m a Source #

Relative version of return.

rbind :: forall (b :: S) (a :: S). Distinct b => Scope b -> m a -> (f a -> m b) -> m b Source #

Relative version of >>=.

Note the two special additions to the usual definition of a relative binding operation:

Scope b is added since is corresponds to the runtime counterpart of the type parameter b.
Distinct b constraint helps to ensure we only work with scopes that are distinct.

Technically, it is also possible add similar components for a parameter. Also, we could probably treat types in S as singletons and extract distinct scopes that way, preserving the more general type signature for rbind.

Instances

Instances details

RelMonad Name Expr Source #	`Expr` is a monad relative to `Name`.
Instance details Defined in Control.Monad.Foil.Example Methods rreturn :: forall (a :: S). Name a -> Expr a Source # rbind :: forall (b :: S) (a :: S). Distinct b => Scope b -> Expr a -> (Name a -> Expr b) -> Expr b Source #
Bifunctor sig => RelMonad Name (AST sig) Source #	`AST sig` is a monad relative to `Name`.
Instance details Defined in Control.Monad.Free.Foil Methods rreturn :: forall (a :: S). Name a -> AST sig a Source # rbind :: forall (b :: S) (a :: S). Distinct b => Scope b -> AST sig a -> (Name a -> AST sig b) -> AST sig b Source #

liftRM :: forall f m (b :: S) (a :: S). (RelMonad f m, Distinct b) => Scope b -> (f a -> f b) -> m a -> m b Source #

Relative version of liftM (an fmap restricted to Monad).