functor-combo-0.0.4: Functor combinators with tries & zippers
FunctorCombo.FixC
Description
Zippers for functor fixpoints
Synopsis
type FixC f = [Der f (Fix f)]Source
Context for functor fixpoints
Context for a regular type
type LocFix f = (FixC f, Fix f)Source
Location in a functor tree -- a zipper
up :: Holey f => LocFix f -> LocFix fSource
Move upward. Error if empty context.
up' :: Holey f => LocFix f -> Maybe (LocFix f)Source
Variant of up. Nothing if empty context.
up
Nothing
down :: Holey f => LocFix f -> f (LocFix f)Source