From: "Sean E. Russell" <ser@...>
Date: 2004-02-26T03:34:12+09:00
Subject: Re: foldl and foldr


--Boundary-02=_7pOPA0zKC9iiONw
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

On Wednesday 25 February 2004 11:57, Eivind Eklund wrote:
> > foldr() can be -- and is, in my example code -- implemented without
> > reverse(), which is the point of having it.
>
> Sorry - I read your original mail a little too fast.  Is this something
> you often find useful?  I have found inject useful, but I've never ended
> up doing reverse.inject, so I question the need for it somewhat.

No, foldr() is less commonly needed -- or, I should say, most folds can be=
=20
done with either foldr or foldl, and of those that can't, the majority are=
=20
*probably* left-associative.  There are a few cases where right-association=
=20
is needed, but I don't run across them much.  Indeed, had I known about=20
inject(), I wouldn't have posted my message.

> As far as I know, rcrchive.net is the official location now.

Thanks.

=2D-=20
### SER  =20
### Deutsch|Esperanto|Francaise|Linux|XML|Java|Ruby|Aikido
### http://www.germane-software.com/~ser  jabber.com:ser  ICQ:83578737=20
### GPG: http://www.germane-software.com/~ser/Security/ser_public.gpg

--Boundary-02=_7pOPA0zKC9iiONw
Content-Type: application/pgp-signature
Content-Description: signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (GNU/Linux)

iD8DBQBAPOp7P0KxygnleI8RAtsNAJ4jDMnz8Bh9PRRMm5xzY8SCylMS0wCeISCT
Or8Eu5EXXf8he5C8i0dAoM0=
=q4KZ
-----END PGP SIGNATURE-----

--Boundary-02=_7pOPA0zKC9iiONw--