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Date:         Mon, 21 Dec 2009 01:03:24 -0500
Reply-To:     Scott Bass <sas_l_739@YAHOO.COM.AU>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Scott Bass <sas_l_739@YAHOO.COM.AU>
Subject:      Is this a macro bug???

Hi,

I have a "loop" macro as follows:

/*--------------------------------------------------------------------- * PROGRAM: loop * DESCRIPTION: A "wrapper" macro to execute code over a list of items * SAS VERSION: SAS 8.2 * DATE: 24 Apr 2006 * AUTHOR: Scott Bass * * MODIFICATIONS: * ============= * Date UID Description * ----------- --- ---------------------------------------------------- * 24 Apr 2006 SLB Initial revision * 17 Jul 2006 SLB Added DLM parameter ---------------------------------------------------------------------*/

%macro loop /*--------------------------------------------------------------------- Invoke the nested macro "%code" over a list of space separated list of items. ---------------------------------------------------------------------*/ (__LIST__ /* Space or character separated list of items (REQ) */ ,DLM=%str( ) /* Delimiter character (REQ). Default is a space. */ ,MNAME=code /* Macro name (Optional). Default is "%code" */ );

/*--------------------------------------------------------------------- Usage:

%macro code; %put &word; %mend; %loop(Hello World);

%let str = Hello,World; %loop(%bquote(&str),dlm=%bquote(,));

%macro mymacro; proc print data=&word; run; %mend;

proc datasets kill nowarn nolist; quit;

data one;x=1;run; data two;y=2;run;

proc sql noprint; select memname into :list separated by '|' from dictionary.tables where libname = "WORK" and memtype = "DATA" ; quit; %loop(&list,dlm=|,mname=mymacro);

proc sql noprint; select trim(value) into :list separated by '^' from your_dataset ; quit; %loop(&list,dlm=^);

----------------------------------------------------------------------- Notes:

The nested macro "%code" must be created at run time before calling this macro.

Use the macro variable "&word" within your %code macro for each token (word) in the input list.

If your input list has embedded blanks, specify a different dlm value.

---------------------------------------------------------------------*/

%local macro parmerr iter;

/* %* check input parameters ; %let macro = &sysmacroname; %parmv(__LIST__, _req=1,_words=1,_case=N)

%if (&parmerr) %then %goto quit; */

%* make sure the iterator is unique ; %* if %code resets the iterator problems occur ; %let iter = _%substr(&sysprocessid,1,6)_; %local &iter;

%let &iter = 1; %let word = %scan(%superq(__list__),&&&iter,%str(&dlm)); %do %while (%superq(word) ne %str()); %&mname /* do not indent macro call */ %let &iter = %eval(&&&iter+1); %let word = %scan(%superq(__list__),&&&iter,%str(&dlm)); %end;

%quit: %mend;

Now, compare the invocation of %loop in the following scenarios:

options mlogic symbolgen;

%macro test; %put *** &word ***; %mend; %loop(Hello World,mname=test);

%macro test(parm=); %put *** &word ***; %mend; %loop(Hello World,mname=test);

%macro test(parm1,parm2,parm3); %put *** &word ***; %mend; %loop(Hello World,mname=test);

The first version works, the 2nd and 3rd versions don't. Any ideas why macro parameters (even if they aren't used) cause the outer %loop macro variable parsing logic to fail? Could this be a bug in macro?

Thanks, Scott


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