union package:Cabal

A union of patterns, e.g. dir{a,*.txt,c}...
Like "Data.List.union", but has O(n log n) complexity instead of O(n^2).
A right-biased version of listUnion. Example:
>>> listUnion [1,2,3,4,3] [2,1,1]
[1,2,3,4,3]
>>> listUnionRight [1,2,3,4,3] [2,1,1]
[4,3,2,1,1]