lens-4.2: Lenses, Folds and Traversals

Copyright(C) 2012-14 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
PortabilityMTPCs
Safe HaskellSafe-Inferred
LanguageHaskell98

Data.Tree.Lens

Description

 

Synopsis

Documentation

root :: Lens' (Tree a) a Source

A Lens that focuses on the root of a Tree.

>>> view root $ Node 42 []
42

branches :: Lens' (Tree a) [Tree a] Source

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

view branches ≡ subForest