Re: [Ocaml-lib-devel] New Library 1: XList

[Brian H. <bh...@sp...>]

On Mon, 17 Mar 2003, fva wrote:

>  Rather than using ExtList which gives the impression of an extension of 
> the signature (maybe there is, I haven't looked into the code, really) 

The only extension to the list signature I made was that I added a
fold_right'.  The only way I could think of to implement fold_right in a
tail-recursive manner was to first reverse the list, and then traverse it.  
My experiments with append show that reversing the list is about 30%
slower than simply doing a non-tail recursion.  So I provided two
functions- fold_right which reverse the list (works correctly for all
lists, slower), and fold_right' which does non-tail-recursion (faster,
doesn't work for all lists).

Brian