Date: Mon, 2 Jul 2001 15:22:49 -0400
Reply-To: "Fehd, Ronald J." <rjf2@CDC.GOV>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: "Fehd, Ronald J." <rjf2@CDC.GOV>
Subject: Re: macro help: reference %global macro vars
Content-Type: text/plain; charset="iso-8859-1"
> From: Ian Whitlock [mailto:WHITLOI1@WESTAT.com]
> This is a nasty version 8 bug.
> You cannot global a local variable.
I agree.
However, you can 'copy' a local mac-var value to a global mac-var.
> In version 6 an error was reported in any attempt to do so.
yes, my memory of error messages supports that.
> In running your
> code under version 8 there are no error messages! Line 82,
> "%global X;", is
> simply ignored. I would very much prefer to leave it as an
> error since it
> is an error and the programmer should be made aware of his mistake.
I was chagrined to _not_ see any error message on this
%global X;
statement. The %put supported my assumption
-- listing the %local value of X --
that once mac-var X had been added to the %local symbol table
there would be no way to access the %global variable.
except, perhaps, thru work-arounds, as provided by other posters
accessing the system tables.
> Who asked for this behavior. Is it a mistake by accident or design?
ill-informed bxor undereducated, I'm sure.
Little birdies will have to rescue themselves from this one.
Ron Fehd the macro maven CDC Atlanta GA USA RJF2@cdc.gov
> -----Original Message-----
> From: Fehd, Ronald J. [mailto:rjf2@CDC.GOV]
> Sent: Monday, July 02, 2001 10:12 AM
> To: SAS-L@LISTSERV.UGA.EDU
> Subject: Re: macro help: reference %global macro vars
>
>
> > From: ZPAN [mailto:zpan@AOL.COM]
> > How can I reference GLOBAL macro x within macro NEW?
>
> > %global x; %*this is unnecessary in open code;
>
> 74 %macro newY(Y=);
> 75 %PUT LOCAL: ;
> 76 %PUT _local_;
> 77 %put GLOBAL X: &x;/* THIS IS TO REFERENCE LOCAL MACRO
> VARIABLE X*/
> 78 %LOCAL X;
> 79 %LET X = &Y.;
> 80 %PUT _local_;
> 81
> 82 %global X;
> 83 %put global or local x: &X.;
> 84 %PUT _local_;
> 85 %mend;
> 86
> 87 %newy(Y=2);
> LOCAL:
> NEWY Y 2
> GLOBAL X: 1
> NEWY X 2
> NEWY Y 2
> global or local x: 2
> NEWY X 2
> NEWY Y 2
> 88 %put global: &x;/* THIS IS TO REFERENCE LOCAL MACRO VARIABLE X*/
> global: 1
>
> You are not going to be able to declare X in a %local symbol table
> -- by having it in the parameter list --
> before you try to access %global X.
>
> This concept is known as masking:
> You can access %global X until you mask it with a %local declaration.
> Your declaration was in the parameter list of macro NEW.
> My example %put the %global X, then declared X %local and
> %put the local
> value. You will not be able to switch back to accessing the %global X.
>
> As always the important question is: Why do you want to do this?
>
> This is major pain in the program for new macro users:
> keeping track of which macro var they are using.
>
> It often shows up as a major Can't-figure-this-out
> when using the same loop index -- I -- in a calling and a
> called macro.
>
> 14 %macro CALLING(A);
> 15 %DO I = 1 %TO 3;%PUT CALLING MSG: &I.;%CALLED(&I);%END;
> 16 %PUT _LOCAL_;%MEND;
> 17 %macro CALLED(B);
> 18 %DO I = 1 %TO 3;%PUT CALLED MSG: &I.;%END;%MEND;
> 19 %CALLING(1);
> CALLING MSG: 1
> CALLED MSG: 1
> CALLED MSG: 2
> CALLED MSG: 3
> CALLING I 5
> CALLING A 1
>
> mac-var I is %local to CALLING
> macro CALLED resets it and increments it thru its loop,
> and on exit, back to CALLING I fails the CALLING loop value and exits.
> To fix this, add a
> %local I;
> to macro CALLED.
>
> Ron Fehd the macro maven CDC Atlanta GA USA RJF2@cdc.gov
> OpSys: WinNT Ver: 8.1
> ---> cheerful provider of TESTED SAS code!*! <---
> By using your intelligence you can sometimes make your
> problems twice as
> complicated.
> -- Ashleigh Brilliant
>
