functor-combo-0.3.6: Functor combinators with tries & zippers

Copyright(c) Conal Elliott 2010
LicenseBSD3
Maintainerconal@conal.net
Stabilityexperimental
Safe HaskellNone
LanguageHaskell98

FunctorCombo.ZipperFix

Description

Zippers for functor fixpoints

Synopsis

Documentation

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 f Source

Move upward. Error if empty context.

up' :: Holey f => Zipper f -> Maybe (Zipper f) Source

Variant of up. Nothing if empty context.

down :: Holey f => Zipper f -> f (Zipper f) Source