Control.Monad.Foil.Relative

Documentation

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

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

Methods

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

Relative version of return.

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

Relative version of >>=.

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

1. Scope b is added since is corresponds to the runtime counterpart of the type parameter b.
2. 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

RelMonad Name Expr

Expr is a monad relative to Name.

Defined in Control.Monad.Foil.Example

Methods

rreturn :: forall (a :: S). Name a -> Expr a

rbind :: forall (b :: S) (a :: S). Distinct b => Scope b -> Expr a -> (Name a -> Expr b) -> Expr b

Bifunctor sig => RelMonad Name (AST sig)

AST sig is a monad relative to Name.

Defined in Control.Monad.Free.Foil

Methods

rreturn :: forall (a :: S). Name a -> AST sig a

rbind :: forall (b :: S) (a :: S). Distinct b => Scope b -> AST sig a -> (Name a -> AST sig b) -> AST sig b