I just wanted to thank all of you for your insightful responses. This has been very useful!<div>--Will K.<br><br><div class="gmail_quote">On Fri, Aug 13, 2010 at 3:21 PM, Will M. Farr <span dir="ltr"><<a href="mailto:wmfarr@gmail.com" target="_blank">wmfarr@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">+1 from me, too. I always have to check myself to remember that the foldl accumulator argument comes in on the *right*. FWIW, OCaml also does it the Haskell way (foldl accumulator on the left, foldr accumulator on the right).<br>
<br>
This also makes the obvious many-argument version more efficient:<br>
<br>
(define (foldl kons knil . lists)<br>
(if (ormap null? lists)<br>
knil<br>
(apply foldl kons (apply kons knil (map car lists)) (map cdr lists))))<br>
<br>
as opposed to<br>
<br>
(define (foldl* kons knil . lists)<br>
(if (ormap null? lists)<br>
knil<br>
(apply foldl* kons (apply kons (append (map car lists) (list knil))) (map cdr lists))))<br>
<br>
The extra append is kinda annoying in the foldl* version....<br>
<font color="#888888"><br>
Will<br>
</font><div><div></div><div><br>
On Aug 13, 2010, at 4:18 PM, Matthias Felleisen wrote:<br>
<br>
><br>
> I privately +1ed Joe, and I all supportive of introducing new folds and phasing out the old ones.<br>
><br>
><br>
> On Aug 13, 2010, at 4:04 PM, Sam Tobin-Hochstadt wrote:<br>
><br>
>> On Fri, Aug 13, 2010 at 3:11 PM, Joe Marshall <<a href="mailto:jmarshall@alum.mit.edu" target="_blank">jmarshall@alum.mit.edu</a>> wrote:<br>
>>> It seems to me that the Haskell version is better.<br>
>><br>
>> The Haskell ordering also has the advantage of fitting with the Typed<br>
>> Racket type system for variable-arity functions.<br>
>> --<br>
>> sam th<br>
>> <a href="mailto:samth@ccs.neu.edu" target="_blank">samth@ccs.neu.edu</a><br>
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