From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: weber Newsgroups: gmane.emacs.help Subject: Re: fif function from On Lisp Date: Tue, 4 Mar 2008 06:12:35 -0800 (PST) Organization: http://groups.google.com Message-ID: References: <5ac4de71-b4e5-4b3d-997c-e438b816740e@d4g2000prg.googlegroups.com> <49e5c6c1-8e7b-4fd3-9e14-aea887195570@n36g2000hse.googlegroups.com> <1580ffe1-31a9-402c-8064-0add67805cac@d62g2000hsf.googlegroups.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1204641842 6421 80.91.229.12 (4 Mar 2008 14:44:02 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 4 Mar 2008 14:44:02 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Mar 04 15:44:19 2008 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1JWYM7-00082X-7X for geh-help-gnu-emacs@m.gmane.org; Tue, 04 Mar 2008 15:42:59 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JWYLa-0002jc-90 for geh-help-gnu-emacs@m.gmane.org; Tue, 04 Mar 2008 09:42:26 -0500 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!postnews.google.com!q78g2000hsh.googlegroups.com!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 65 Original-NNTP-Posting-Host: 189.32.73.15 Original-X-Trace: posting.google.com 1204639955 6657 127.0.0.1 (4 Mar 2008 14:12:35 GMT) Original-X-Complaints-To: groups-abuse@google.com Original-NNTP-Posting-Date: Tue, 4 Mar 2008 14:12:35 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: q78g2000hsh.googlegroups.com; posting-host=189.32.73.15; posting-account=7GrjgQoAAAD6slWURausdJnhFDkmQYC8 User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.12) Gecko/20080201 Firefox/2.0.0.12,gzip(gfe),gzip(gfe) X-HTTP-Via: 1.1 stargate.datacom:3128 (squid/2.6.STABLE5) Original-Xref: shelby.stanford.edu gnu.emacs.help:156675 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:52046 Archived-At: On Mar 4, 11:07 am, weber wrote: > On Mar 4, 10:59 am, weber wrote: > > > > > On Mar 4, 9:53 am, bojohan+n...@dd.chalmers.se (Johan Bockg=E5rd) wrote:= > > > > weber writes: > > > > Hi folks. > > > > For some reason this function from On Lisp doesn't work: > > > > > (defun fif (a b &optional c) > > > > '(lambda (x) > > > > (if (funcall a x) > > > > (funcall b x) > > > > (unless (null c) (funcall c x))))) > > > > > I should be able to call it like this: > > > > > (mapcar (fif 'zerop '1+ 1-) '(0 1 2 3) =3D> (1 0 1 2) > > > > > but i'm probably missing something that is differs from Common Lisp = to > > > > Elisp. > > > > The code above doesn't work in Common Lisp either, but anyway, Emacs > > > Lisp doesn't have lexical closures (yet). > > > > (info "(elisp) Extent") > > > > -- > > > Johan Bockg=E5rd > > > Hm. Does that snippet really depends on lexical closures? > > I just need that function to expand to this: > > > (mapcar (lambda (x) (if (funcall 'zerop x) (funcall '1+ x) (funcall > > '1- x))) > > '(0 1 2 3)) > > > ... maybe I can solve it with a macro then? > > > -weber > > Ok, i can. > Tks anyway. > > (defmacro fif (a b &optional c) > `(lambda (x) > (if (funcall ,a x) > (funcall ,b x) > (unless (null ,c) (funcall ,c x))))) > > -weber Just needed to post a correct version: (defmacro fif (a b &optional c) `(lambda (x) (if (funcall ,a x) (funcall ,b x) (if (null ,c) x (funcall ,c x))))) -weber