[Ocaml-lib-devel] Re: Idea with ExtList.fold_right

[Alan P. <ap...@re...>]

In article <Pin...@ea...>, Brian Hurt wrote:
> On Mon, 16 Jun 2003, Alan Post wrote:
>> 
>> Why not simply provide "fold" which does a fold_left, and put in a
>> comment that the user should reverse the list arg if she really wants
>> a fold_right?  As you said, it isn't possible to walk a list
>> backwards, so why pretend?
> 
> The short answer is that the standard library provides a fold_right, 
> rightly or wrongly.  If we're angling to replace the standard libraries, 
> we need to not break any code that depends on them.  Adding functions is 
> OK, deleting functions I'd approach with great trepidation.

That sounds sensible to me.  How about doing the compatible thing,
then, using the stack-gobbling approach the existing library uses, and
putting in a comment that the user should avoid this function.