%macro mu_wordscan
(string=
,root=_root_
,numw=_numw_
,delim=
,qtype=UNQUOTE
) / STORE SOURCE des='V1.0.0.19';

%*****************************************************************************
FILENAME: MU_WORDSCAN.SAS
VERSION: 1.0
DEVELOPER: PPD
PLATFORM: SAS 8.2, 9.1.3, and 9.2 on PC SAS
PURPOSE: This macro scans a character string and returns:
	1.	an array of GLOBAL macro variables consisting of the individual elements 
		of the string as defined by a user supplied delimiter.
	2.	optionally, a GLOBAL macro variable containing the number of elements in the 
		string as defined by a user supplied delimiter
PARAMETERS:
STRING	=	The string of words to parse	
ROOT	=	The root of the macro variables that are to be defined (default= _root_)
NUMW	=	The number of words parsed (default = _numw_)
DELIM	=	The delimiter separating each word in the string

MU_WORDSCAN_RC = return code generated by this program
	0 = macro ran successfully
	1 = macro did not run successfully
	
MODIFIED BY:		DATE:
******************************************************************************;

%*EXAMPLES:

%MU_WORDSCAN(string=this is a test)
	This macro will parse the parameter STRING and return global macro variables:
	_ROOT_1=this 
	_ROOT_2=is 
	_ROOT_3=a 
	_ROOT_4=test 
	_NUMW_=4

%MU_WORDSCAN(string=usubjid rxstart rxstop durat, root=dosvar, numw=num_dosvar)
	This will resolve the following gloabl macro variables:
	DOSVAR1=usubjid
	DOSVAR2=rxstart
	DOSVAR3=rxstop
	DOSVAR4=durat
	NUM_DOSVAR=4

%let varlist=She!sells!sea!shells!by!the!seashore 
%MU_WORDSCAN(string=&varlist, root=twist, numw=num_twist, delim=!)
	This will resolve the following gloabl macro variables:
	TWIST1=she
	TWIST2=sells
	TWIST3=sea
	TWIST4=shells
	TWIST5=by
	TWIST6=the
	TWIST7=seashore
	NUM_TWIST=7
******************************************************************************;

%local word count;
%global &SYSMACRONAME._RC;
%let &SYSMACRONAME._rc = 0;
%let abort = no;
%if &abort = yes %then %goto exit;

%let count=1;

%if %sysevalf( %superq(string)= ,boolean )=1 %then %do;
	%put %str(ALERT)_I: parameter STRING is empty in &SYSMACRONAME call;
%end;
%if &root = %str() %then %do;
	%put %str(ALERT)_I:  parameter ROOT is empty in &SYSMACRONAME call.  _ROOT_ will be assigned.;
	%let root=_root_;
%end;
%if &numw = %str() %then %do;
	%put ALERT_I: parameter NUMW is empty in &SYSMACRONAME call.  _NUMW_ will be assigned;
	%let numw = _numw_;
%end;
%else %if %upcase(&numw) = NUMW %then %do;
	data _null_;
	put "ALERT_P: Attempt to GLOBAL a name (NUMW) which exists in a local environment in &SYSMACRONAME call. Program will ABORT.";
	put "ALERT_P: Assign  a different name to the parameter NUMW in &SYSMACRONAME call.";
	call symputx("&SYSMACRONAME._rc", 1);
	ABORT;
	run;
%end;

%if %sysevalf( %superq(delim)= ,boolean )=1 %then %let delim = %str( );

%* scans the &STRING and finds the first value with the value of count, which is one and
   has the delimeter set as a &delim;

%let word=%qscan(&string,&count,&delim);

%* while &WORD is not missing then &ROOT&COUNT is equal to &WORD. Also &COUNT represents
   the incremental increase. The &STRING is scanned for the first argument. ;

%do %while( %sysevalf( %superq(word)= ,boolean )=0 ) ;
          %global &root&count;

                 %if %qupcase(&qtype.)=UNQUOTE %then %do ; %let &root&count=%unquote(%bquote(&word.));  %end ;
                    %else %if %qupcase(&qtype.)=SUPERQ %then %do ; %let &root&count=%superq(word); %end ;  
                    %else %if %qupcase(&qtype.)=NRBQUOTE %then %do ; %let &root&count=%nrbquote(&word.); %end ;  
                 %let count=%eval(&count+1);
                 %let word=%qscan(&string,&count,&delim);
%end;

%* if a value has been specified for macro variable NUMW then a macro variable of that name
   will be created containing a count of the number of words in the STRING;

%if %length(&numw) > 0 %then %do;
     %global &numw;
     %let &numw = %eval(&count-1);
%end;

%**If more than one word, check that the delimiter used in macro variable is the same as the delimiter macro variable***;
%let countw=0;
%if "&string" ne "" %then %let countw=%sysfunc(countw(&string,' #£$%^&*!@~|/:;,+'));

%if &countw gt 1 %then %do;
	%if %index(&string,&delim)=0 %then %put %str(ALERT)_I: Check that the delimiter is correct;
%end;

%exit:

%put &SYSMACRONAME._RC = &&&SYSMACRONAME._RC;
%mend mu_wordscan;