Trees with polymorphic paths to nodes, combining properties of Rose Trees and Tries.
A rose tree is a tree of trees, where every node contains a leaf and set of sub-trees. A trie is a tree structure where each node can be accessed using a "path," where a path is a list of keys. A rose-trie does both. RoseTries are best used in situations where every leaf in the Trie needs to accessible by a list of polymorphic path elements.
The underlying implementation is based on Data.Map, from the Haskell Platform's "containers" package. So unlike the ordinary rose tree, where each node contains a list of sub-trees, the RoseTrie contains a Map of sub-trees, where each key in the Map forms a single link in the trie path. As a result, the path for the RoseTrie is a list data type that is polymorphic over list elements which instantiate both the Prelude.Ord and Prelude.Eq type classes.
Operating on a RoseTrie with a path of length p performs up to p times a number of O(log n) Map operations on each of the sub-tree Map structures containing n elements, therefore path lookups and insertions in a RoseTrie data structure are on the order of O(p * log n) time complexity.
This library was originally part of the Dao package, but has been branched into it's own package in the hopes that it will be useful in a wider variety of projects.