23 Jan
2001
23 Jan
'01
12:52 p.m.
Pardon? map is data parallel. foldr not so obviously...
Sorry, a slip on my behalf: foldr in general is not data parallel, but if the function being folded with is associative then foldr can be implemented by a parallel (balanced binary-tree) reduction in time O(log n), where n is the length of the list. A compiler needs the information that or is a fold over an associative operation in order to employ such a parallel implementation. Björn Lisper