Date:         Mon, 7 Feb 2005 21:38:36 +0000
Reply-To:     iw1junk@COMCAST.NET
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Ian Whitlock <iw1junk@COMCAST.NET>
Subject:      Bug in %SCAN (was Re: %substrw)
Comments: cc: LZ <lzhang9830@YAHOO.COM>

Hi Ian,
   Well-written macro!  Two suggestions:
   Test case 1:
   %let s1= %selwseq(%str(a, b, c, d), 2, 2, dlim=%str(,));
   %put s1=&s1;
        It returns "b C" instead of "b, c"
   Test case 2:
   %let s2 = %selwseq(%str(a, b, max(c,d), d), 2, 2, dlim=%str(,));
   %put s2=&s2;
        It returns "b  max(c". I
        It will be better if the macro can return "b, max(c,d)"
LZ
<snip>
=====================================
LZ,

Thanks.  I do not get the problem that you indicate in case 1, when running
the Learning Edition 1.3.0.161 under Windows XP.

Fixing the problem that you indicate in case 2 would be hard since %SCAN
does not support this sort of thing.  Incidentally, in thinking about this
response I tried the following.

WARNING: Only the Base product and the SAS/STAT product have been tested
for use with
         VALIDVARNAME=ANY. Other use of this option is considered
         experimental and may cause
         undetected errors.
2          OPTIONS VALIDVARNAME=ANY;
NOTE: Some of your options or statements may not be supported with the
activex or java devices.
       For further information, please contact Technical Support.
3          OPTIONS DEV=ACTIVEX;
4          ODS LISTING;
5          %put ===========================;
===========================
ERROR: Open code statement recursion detected.
6          %put %scan ( a "b c", 2 , %str( )) ;
7          %put ===========================;
8          run;
9          quit;
10

Anyone have any idea where the recursion is coming from?  I get the same
result in version 9.1.2 with macro quoting by %SUPERQ.  Although SCAN works as expected, you cannot cheat and use

     %SYSFUNC(SCAN( a "b c", 2 , %str( )))

since it has the same recursion problem.  However SCAN in a DATA step works as expected yielding "b.

Ian Whitlock