Tree from nesting levels: Difference between revisions

:# a generic ''forestFromNestLevels'' function to map from a normalised input list to a generic tree, and

:# a standard catamorphism over trees (''foldTree'') to generate both the nested list format, and the round-trip regeneration of a sparse list from the generic tree.

 

-- forestFromNestLevels :: [(Int, a)] -> [Tree a]