On Tue, 10 Jul 2012 09:04:31 +0200, Jonathan M Davis <jmdavisProg at gmx.com> wrote: > The problem is that map is lazy, so it can't be a random access range, Sure it can. If the underlying range is random-access or bidirectional, so can map be. What can't be (as easily) done is caching of elements. -- Simen