containers-0.4.0.0: Assorted concrete container types

Portabilityportable
Stabilityexperimental
Maintainerlibraries@haskell.org

Data.Tree

Contents

Description

Multi-way trees (aka rose trees) and forests.

Synopsis

Documentation

data Tree a Source

Multi-way trees, also known as rose trees.

Constructors

Node 

Fields

rootLabel :: a

label value

subForest :: Forest a

zero or more child trees

type Forest a = [Tree a]Source

Two-dimensional drawing

drawTree :: Tree String -> StringSource

Neat 2-dimensional drawing of a tree.

drawForest :: Forest String -> StringSource

Neat 2-dimensional drawing of a forest.

Extraction

flatten :: Tree a -> [a]Source

The elements of a tree in pre-order.

levels :: Tree a -> [[a]]Source

Lists of nodes at each level of the tree.

Building trees

unfoldTree :: (b -> (a, [b])) -> b -> Tree aSource

Build a tree from a seed value

unfoldForest :: (b -> (a, [b])) -> [b] -> Forest aSource

Build a forest from a list of seed values

unfoldTreeM :: Monad m => (b -> m (a, [b])) -> b -> m (Tree a)Source

Monadic tree builder, in depth-first order

unfoldForestM :: Monad m => (b -> m (a, [b])) -> [b] -> m (Forest a)Source

Monadic forest builder, in depth-first order

unfoldTreeM_BF :: Monad m => (b -> m (a, [b])) -> b -> m (Tree a)Source

Monadic tree builder, in breadth-first order, using an algorithm adapted from Breadth-First Numbering: Lessons from a Small Exercise in Algorithm Design, by Chris Okasaki, ICFP'00.

unfoldForestM_BF :: Monad m => (b -> m (a, [b])) -> [b] -> m (Forest a)Source

Monadic forest builder, in breadth-first order, using an algorithm adapted from Breadth-First Numbering: Lessons from a Small Exercise in Algorithm Design, by Chris Okasaki, ICFP'00.