Thomas Conway wrote:
Well, maybe I shoud be asking a higher level question then.
I have a function
tidy = reverse . dropWhile punk . reverse . dropWhile punk where punk = isPunctuation . chr . fromIntegral
which is leading to a significant amount of allocation, and you can see why.
The way I'd like to write it is
tidy = dropWhile punk . dropWhileEnd punk where ....
which has the obvious advantage of avoiding quite a bit of intermediate allocation.
Is there a another way?
I note that since I'm using a nice declarative language, the compiler CLEARLY should be transforming the first form into the second. :-)
The NDP library will implement this kind of fusion at some point (hopefully this year). We have a fairly clear idea of how to do it but not enough time. Roman