29 Nov
2007
29 Nov
'07
4:06 p.m.
On Thu, 29 Nov 2007, Bryan O'Sullivan wrote:
Henning Thielemann wrote:
I thought operations like "foldl'" and "drop" must be very fast on arrays (especially UArray) with appropriate pointer tricks,
These kinds of functions are only much use on one-dimensional arrays, which look sufficiently list-like that the ideas translate fairly cleanly. For higher dimensions, there are enough options in terms of traversal direction and what exactly e.g. a fold should fold over (single elements? lower-dimensional slices?) that a sensible API doesn't exactly leap out.
That's unfortunately true. However, for my application (signal processing) I need mostly one-dimensional arrays and they should support fast "foldl'", slice, "build".