Test case : Bubble sort using Algol 68

BEGIN [25] INT a;
      INT n := 0;
      FOR i TO UPB a WHILE read (a[i]); a[i] /= 0 DO n +:= 1 OD;
      WHILE BOOL swap := FALSE;
	    FOR i TO n-1
	      DO IF a[i] > a[i+1]
		   THEN INT temp = a[i];
			a[i] := a[i+1];
			a[i+1] := temp;
			swap := TRUE
		 FI
	      OD;
	    swap
	 DO SKIP OD;
      print ((a[:n], newline))
END