Copyright	(C) 2012-16 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	provisional
Portability	MTPCs
Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Tree.Lens

Description

Synopsis

root :: forall a f. Functor f => (a -> f a) -> Tree a -> f (Tree a)
branches :: forall a f. Functor f => ([Tree a] -> f [Tree a]) -> Tree a -> f (Tree a)

Documentation

root :: forall a f. Functor f => (a -> f a) -> Tree a -> f (Tree a) Source #

A Lens that focuses on the root of a Tree.

>>> view root $ Node 42 []
42

branches :: forall a f. Functor f => ([Tree a] -> f [Tree a]) -> Tree a -> f (Tree a) Source #

A Lens returning the direct descendants of the root of a Tree

view branches ≡ subForest