Date:         Wed, 2 Nov 2005 19:03:05 +1100
Reply-To:     Scott Bass <usenet739_yahoo_com_au@ALFREDO.CC.UGA.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Scott Bass <usenet739_yahoo_com_au@ALFREDO.CC.UGA.EDU>
Subject:      Re: complement of a macro variable
Comments: To: sas-l@uga.edu

Oops, to be totally precise, the line

&string;

should probably be

&string  (no trailing semicolon)

Add the trailing semicolon in your calling program.

For example, with the previous macro, this code would fail with a syntax
error:

data one;
   array stuff{*} %rename(&varlist,&varpart,b) even more vars a b c;
run;

"Scott Bass" <usenet739_yahoo_com_au> wrote in message
news:43687114$0$1713$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
>
> "satya" <satyaanam@hotmail.com> wrote in message
> news:1130900904.700741.269080@g47g2000cwa.googlegroups.com...
>> dear sas-lers,
>> here is my problem for today.
>>
>> i have a macro variable that list some variables:
>> %let varlist=c_d_sex c_d_wei1 c_d_wei2 c_d_age1 c_d_age2 c_d_age3;
>> and a corresponding macroavr that list a part of it, say;
>> %let varpart=c_d_wei1 c_d_wei2;
>> i want to create a third macrovar, corresponding to varlist, in which
>> each single string of the complement to varpart has a different prefix
>> (b instead of c) that is:
>> varlist1=b_d_sex c_d_wei1 c_d_wei2 b_d_age1 b_d_age2 b_d_age3
>
> Perhaps this meets your needs:
>
> 115  %let varlist=c_d_sex c_d_wei1 c_d_wei2 c_d_age1 c_d_age2 c_d_age3;
> 116  %let varpart=c_d_wei1 c_d_wei2;
> 117
> 118  %macro rename(list,exempt,prefix);
> 119     %local string word;
> 120     %let i=1;
> 121     %let word = %scan(&list,&i,%str( ));
> 122     %do %while (&word ne );
> 123        %if %index(&exempt,&word) %then
> 124           %let string = &string &word;
> 125        %else
> 126           %let string = &string
> &prefix.%substr(&word,%index(&word,%str(_)));
> 127        %let i=%eval(&i+1);
> 128        %let word = %scan(&list,&i,%str( ));
> 129     %end;
> 130     &string;
> 131  %mend;
> 132
> 133  options mprint;
> 134  data one;
> 135     array stuff{*} %rename(&varlist,&varpart,b);
> MPRINT(RENAME):   b_d_sex c_d_wei1 c_d_wei2 b_d_age1 b_d_age2 b_d_age3;
> 136  run;
>
> The line:
>
> %let string = &string &prefix.%substr(&word,%index(&word,%str(_)));
>
> will find the first occurance of an underscore in the current word, and
> will add the prefix to the rest of the string to the right of the
> underscore (including the underscore).
>
>>
>> Here is important to have the same order of varlist: i will use this
>> macrovar to define an array in a subsequent data step and has to match
>> to another similar defined array.
>>
>> Thanks in advance for any help
>> satya
>> ps i would also appreciate some links to resources, if any, that
>> teaches this kind of management with macro variables
>
> Read the SAS Macro Language Reference.  That's all I've ever read (plus
> lots of practice).
>