FunctorCombo.ZipperReg

Documentation

type Context t = [Der (PF t) t]

Context for a regular type

type Zipper t = (Context t, t)

Zipper for a regular type. Also called "location"

up :: (Regular t, Holey (PF t)) => Zipper t -> Zipper t

Move upward. Error if empty context.

up' :: (Regular t, Holey (PF t)) => Zipper t -> Maybe (Zipper t)

Variant of up. Nothing if empty context.

down :: (Regular t, Holey (PF t)) => Zipper t -> PF t (Zipper t)