/* Removes trailing and leading blanks from the argument. */
%TRIM_BLANKS:
   PROCEDURE (Text) RETURNS (CHARACTER);
		DECLARE Text CHARACTER;
		DECLARE J FIXED;

		/* First remove trailing blanks. */
		DO J = LENGTH(Text) TO 1 BY -1;
			IF SUBSTR(Text, J, 1) ^= ' ' THEN
				DO;
					Text = SUBSTR(Text, 1, J);
					/* Now remove leading blanks. */
					DO J = 1 TO LENGTH(Text);
						IF SUBSTR(Text, J, 1) ^= ' ' THEN RETURN (SUBSTR(Text, J));
					END;
				END;
			END;
		RETURN ('');
	%END TRIM_BLANKS;
	%ACTIVATE TRIM_BLANKS;

/* Finds the position of the left-most letter in Text. */
/* It returns zero if there is no letter. */
%LETTER:
   PROCEDURE (Text) RETURNS (FIXED);
		DECLARE Text CHARACTER;
		DECLARE J FIXED;

		DO J = 1 TO LENGTH (Text);
			IF INDEX('ABCDEFGHIJKLMNOPQRSTUVWXYZ', SUBSTR(Text, J, 1)) > 0 THEN
				RETURN (J);
		END;
		RETURN (0);
	%END LETTER;

%SEARCHING:
   PROCEDURE(String, Sub) RETURNS (FIXED);
      DECLARE (String, Sub) CHARACTER;
      DECLARE Ch CHARACTER;
      DECLARE (J, K) FIXED;

      DO J = 1 TO LENGTH(String);
         Ch = SUBSTR(String, J, 1);
         K = INDEX(Sub, Ch);
         IF K > 0 THEN RETURN (J);
      END;
      RETURN (0);
   %END SEARCHING;

%INITIAL_VALUES:
   PROCEDURE (Specification);
		DECLARE Specification CHARACTER;
		DECLARE (Initial_Value, Final_Value, Increment,
			Control_Variable, Initial_Expression, Variable) CHARACTER;
		DECLARE (Ch, Temp, Temp2) CHARACTER;
		DECLARE (K, L, M, N, H) FIXED;
DECLARE Trips FIXED;

		/* Convert to upper case. */
		Specification = TRANSLATE (Specification, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
							'abcdefghijklmnopqrstuvwxyz');

		K = VERIFY(Specification, ' '); /* deblank. */
		IF K > 0 THEN Specification = SUBSTR(Specification, K);
		K = INDEX (Specification, ' DO ');
		IF K = 0 THEN
			DO;
				NOTE ('Iterative specification must be of the form (J DO j = 10 to 20.', 8);
				RETURN;
			END;
		Initial_Expression = SUBSTR(Specification, 1, K);
		Specification = SUBSTR(Specification, K+3);
		/* Remove blanks from Initialization_Expression. */
		Temp = '';
		DO K = 1 TO LENGTH(Control_Variable);
			Ch = SUBSTR(Control_Variable, K, 1);
			IF Ch ^= ' ' THEN
				Temp = Temp || SUBSTR(Control_Variable, K, 1);
		END;
		Control_Variable = Temp;

		K = VERIFY(Specification, ' '); /* deblank. */
		IF K > 0 THEN Specification = SUBSTR(Specification, K);

		K = INDEX (Specification, '=');
		IF K = 0 THEN
			DO;
				NOTE ('Equal sign expected.', 8);
				RETURN;
			END;
		Control_Variable = SUBSTR(Specification, 1, K-1);

		Specification = SUBSTR (Specification, K+1);
		/* Expect an initial value. */
		K = VERIFY(Specification, ' '); /* deblank. */
		IF K > 0 THEN Specification = SUBSTR(Specification, K);

		K = INDEX (Specification, ' TO ');
		IF K = 0 THEN
			DO;
				NOTE ('TO missing from initialization.', 8);
				RETURN;
			END;
		Initial_Value = SUBSTR(Specification, 1, K-1);
		Specification = SUBSTR(Specification, K+3);
		K = VERIFY(Specification, ' '); /* deblank. */
		IF K > 0 THEN Specification = SUBSTR(Specification, K);
		Final_Value = Specification;

NOTE ('CONTROL VARIABLE=' || Control_Variable || ' Initial_Expression=' ||
Initial_Expression || '*');

		/* Check whether tihe initial_Expression contains a single elemeent or contains an expression. */
      H = VERIFY (Initial_Expression, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789 ');
      /* If H > 0 then parentheses are required around the constants. */

		/* Generate the constants. */
		DO K = Initial_Value TO Final_Value;
			IF H = 0 THEN Temp = ''; ELSE Temp = '(';
			Temp2 = Initial_Expression;
Trips = 1;
MORE:
			L = SEARCHING(Temp2, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'); /* Look for a letter, */
					/* indicating the start of an identifier. */
			IF L > 1 THEN
				DO;
					IF SUBSTR(Temp2, 1, L-1) ^= ' ' THEN Temp = Temp || SUBSTR(Temp2, 1, L-1);
					Temp2 = SUBSTR(Temp2, L); /* Bring an identifier to the start of the string. */
				END;
			IF L = 0 THEN /* there is no identifier, or no more identifiers. */
				DO;
					NOTE ('No more identifiers.  Quitting', 0);
					GO TO DONE;
				END;
			L = 1;

			M = VERIFY (Temp2, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_', L);
					/* Look for the end of an identifier. */
			IF M = 0 THEN
            DO;
   				Variable = SUBSTR(Temp2, L);
               Temp2 = '';
            END;
			ELSE
				DO;
               Variable = SUBSTR (Temp2, L, M-L);
      			Temp2 = SUBSTR(Temp2, M);
            END;
			IF Variable = Control_Variable THEN
				Temp = Temp || TRIM_BLANKS(K);
			ELSE
				Temp = Temp || Variable;
note ('Temp2=' || Temp2 || ' Temp=' || Temp);
Trips = Trips + 1;
IF Trips > 10 THEN RETURN;
			IF LETTER(Temp2) > 0 THEN GO TO MORE;

DONE:
         IF H > 0 THEN Temp = Temp || ')'; /* An expression required parentheses. */
			ANSWER(Temp);
			IF K < Final_Value THEN ANSWER(',');
		END;
%END INITIAL_VALUES;
%ACTIVATE INITIAL_VALUES;