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