How does %sysfunc(countw(... get resolved in a %do loop

[Tom]

There appears to be some interaction between defining the macro and parsing the %DO statement.  Because the %SYSFUNC() call works fine outside of a macro. 

And it works fine inside the macro if used in a simple %LET statement instead.  

So you could add a separate macro variable to store the upper bound for the %DO loop.

%macro split_terms;
%local terms n i ;
%let terms = %str(This is a term; This is another term, with a comma; And this is a third term);
%let n=%sysfunc(countw(&terms,%str(;)));
%do i = 1 %to &n;
  %put &=i %scan(&terms, &i, %str(;));
%end;
%mend;

Or you could store the delimiter into a macro variable which has the advantage of needed to set the delimiter in only one place.

%macro split_terms;
%local terms dlm i ;
%let terms = %str(This is a term; This is another term, with a comma; And this is a third term);
%let dlm=%str(;);
%do i = 1 %to %sysfunc(countw(&terms,&dlm));
  %put &=i %scan(&terms,&i,&dlm);
%end;
%mend;

Note that adding single quotes or double quotes to the list of delimiter characters will only work properly if the string being scanned/parsed does not include that character.  If it does then using both quote and semicolon as the delimiter will produce different results than using only semicolon.

[Saxi63]

Dear SAS Macro Guru's

This is a known issue at our R&D.
It is unclear when this will be fixed.
Until then, you need to use a new Macro-Variable for the %to value.
regards
Karl-Heinz

%macro split_terms;
%let terms = %str(This is a term; This is another term, with a comma; And this is a third term) ;
%let NUMBER=%sysfunc(countw(&terms, %str(%;))) ;
%do i = 1 %to &Number;
%put %scan(&terms, &i, %str(%;));
%end;
%mend;
%split_terms;

[yabwon]

"It is unclear when this will be fixed." -  question is: is there anyone who still knows how to fix it for macro processor 😉

Bart