Date:         Wed, 27 Oct 2004 14:49:25 -0400
Reply-To:     "Richard A. DeVenezia" <radevenz@IX.NETCOM.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Richard A. DeVenezia" <radevenz@IX.NETCOM.COM>
Subject:      Re: Attempt to %GLOBAL a name which exists in a local environment

Huang, Ya wrote:
> Hi there,
>
> Is there anyway I can make a parameter of a macro to be
> a global macro var ?
>
> 1    %macro a(parm=);
> 2    %global parm;
> 3    %mend;
> 4
> 5    %a(parm=HDL);
> ERROR: Attempt to %GLOBAL a name (PARM) which exists in a local
> environment.
>
> Basically, I want to use &parm somewhere else, but it won't been
> seen unless I make it global macro var. Declare it as a global
> doesn't work as shown above.
>


You can't promote the scope of a local variable into the callers scope.

You will need to come up with a 'contract' between macro A and the place
that wants to use the value passed to A.

The contract in this case is simply agreeing upon a global macro variable
name that does not occur in the scope of A (or any other scope wishing to
use this value made globally available) and transferring the value into it.

%macro A(parm=);
  %global g_parm;  %* define contract;
  %let g_parm=&parm; %* transfer;
  %* use either &parm or &g_parm in A;
%mend;

%A(parm=HDL)
...
...
title "&g_parm was yada"; %* use contract;


--
Richard A. DeVenezia
http://www.devenezia.com/