functor-combo-0.1.1: Functor combinators with tries & zippers
FunctorCombo.ZipperFix
Description
Zippers for functor fixpoints
Synopsis
type Context f = [Der f (Fix f)]Source
Context for functor fixpoints
Context for a regular type
type Zipper f = (Context f, Fix f)Source
Zipper for a functor tree. Also called "location"
up :: Holey f => Zipper f -> Zipper fSource
Move upward. Error if empty context.
up' :: Holey f => Zipper f -> Maybe (Zipper f)Source
Variant of up. Nothing if empty context.
up
Nothing
down :: Holey f => Zipper f -> f (Zipper f)Source