Elm implementation of Buchheim, Junger and Leipert's tree layout algorithm.
This package exposes treeLayout, which returns a dictionary of node identifiers with x and y coordinates
for a given 'distance' (used as a constant for x spacing) and 'nodes'
(a list of hierarchy descriptors starting with the root, represented by tuples of node identifier and parent node identifier).
Example usage:
treeLayout 2 [ ( "a", Nothing ), ( "b", Just "a" ), ( "c", Just "a" ) ]
--> (Dict.fromList [ ( "a", { x = 0, y = 1 } ), ( "b", { x = -1, y = 2 } ), ( "c", { x = 1, y = 2 } ) ])The pseude code written by (Buchheim, Junger and Leipert, 2006) implements aesthetic rules defined by (Walker, 1989) in a linear time for trees of unbounded degree.
This library does not render the tree, so that the rendering logic could be kept separate.