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