Date:         Fri, 16 Jan 2009 09:19:02 -0600
Reply-To:     "./ ADD NAME=Data _null_," <iebupdte@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "./ ADD NAME=Data _null_," <iebupdte@GMAIL.COM>
Subject:      Re: question about sas macro variables
Comments: To: karma <dorjetarap@googlemail.com>
In-Reply-To:  <d6a0d8f10901160605u7fbf3e85y211291834b8cc6f1@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

On 1/16/09, karma <dorjetarap@googlemail.com> wrote:
> I think this raises another interesting question, can SAS macro create
> macro code that is executable at a later time? As far as I know, Lisp
> allows macro code to create macro code ad infinitum. I don't think SAS
> does allow this, but I would be happy to be proven wrong on this. An
> example:
>
> %let c = %superq(%put 1;);
> %unquote(c);

This doesn't work because SUPERQ only works on macro variables and the
unquote is missing & for &C.  But it can be made to work see lines 1
and 2 below.  The rest is a macro that writes a macro.  I can't think
of a use for this today but I think I actually coded something similar
many years ago when I was "macro happy".



1          %let c = %nrstr(%%put NOTE: &systime;);
2          %unquote(&c);
NOTE: 09:08
3
4
5          %macro writes1(name=hello);
6             %let macro = %nrstr(%%)macro &name(called=&sysmacroname)
%nrstr(; %%put NOTE: MY name is &sysmacroname,
6        ! called by &called; %%mend;);
7             %put _local_;
8             %unquote(&macro)
9             %unquote(%&name)
10            %mend writes1;
11
12
13         %writes1;
WRITES1 MACRO    macro hello(called=WRITES1)     put NOTE: MY name is
sysmacroname  called by  called   mend
WRITES1 NAME hello
NOTE: MY name is HELLO, called by WRITES1