BEGIN

   CLASS ITEM;;

   CLASS ITEMARRAY(N); INTEGER N;
   BEGIN
      REF(ITEM) ARRAY DATA(1:N);
      OUTTEXT("NEW ITEMARRAY WITH "); OUTINT(N, 0); OUTTEXT(" ELEMENTS");
      OUTIMAGE;
   END;

   CLASS ARRAYLIST;
   BEGIN

      PROCEDURE EXPAND(N); INTEGER N;
      BEGIN
         INTEGER I;
         REF(ITEMARRAY) TEMP;
         OUTTEXT("EXPAND TO CAPACITY "); OUTINT(N, 0); OUTIMAGE;
         TEMP :- NEW ITEMARRAY(N);
         FOR I := 1 STEP 1 UNTIL SIZE DO
            TEMP.DATA(I) :- ITEMS.DATA(I);
         ITEMS :- TEMP;
      END;

      PROCEDURE ADD(T); REF(ITEM) T;
      BEGIN
         IF SIZE + 1 > CAPACITY THEN
         BEGIN
            CAPACITY := 2 * CAPACITY;
            EXPAND(CAPACITY);
         END;
         SIZE := SIZE + 1;
         ITEMS.DATA(SIZE) :- T;
         OUTTEXT("SIZE IS "); OUTINT(SIZE, 0); OUTIMAGE;
      END;

      PROCEDURE REMOVE(I); INTEGER I;
      BEGIN
        INTEGER J;
        IF I < 1 OR I > SIZE THEN ERROR("REMOVE: INDEX OUT OF BOUNDS");
        FOR J := I STEP 1 UNTIL SIZE - 1 DO
          ITEMS.DATA(J) :- ITEMS.DATA(J + 1);
        ITEMS.DATA(SIZE) :- NONE;
        SIZE := SIZE - 1;
      END;

      REF(ITEM) PROCEDURE GET(I); INTEGER I;
      BEGIN
         IF I < 1 OR I > SIZE THEN ERROR("GET: INDEX OUT OF BOUNDS");
         GET :- ITEMS.DATA(I);
      END;

      INTEGER CAPACITY;
      INTEGER SIZE;
      REF(ITEMARRAY) ITEMS;

      CAPACITY := 20;
      SIZE := 0;
      EXPAND(CAPACITY);

   END;


   ITEM CLASS TEXTITEM(TXT); TEXT TXT;;

   ARRAYLIST CLASS TEXTARRAYLIST;
   BEGIN
      PROCEDURE ADD(T); TEXT T;
         THIS TEXTARRAYLIST QUA ARRAYLIST.ADD(NEW TEXTITEM(T));
      TEXT PROCEDURE GET(I); INTEGER I;
         GET :- THIS TEXTARRAYLIST QUA ARRAYLIST.GET(I) QUA TEXTITEM.TXT;
   END;


   ITEM CLASS REALITEM(X); REAL X;;

   ARRAYLIST CLASS REALARRAYLIST;
   BEGIN
      PROCEDURE ADD(X); REAL X;
         THIS REALARRAYLIST QUA ARRAYLIST.ADD(NEW REALITEM(X));
      REAL PROCEDURE GET(I); INTEGER I;
         GET := THIS REALARRAYLIST QUA ARRAYLIST.GET(I) QUA REALITEM.X;
   END;


   REF(TEXTARRAYLIST) LINES;
   REF(REALARRAYLIST) REALS;
   INTEGER I;

   LINES :- NEW TEXTARRAYLIST;
   LINES.ADD("WE");
   LINES.ADD("HAVE");
   LINES.ADD("SEEN");
   LINES.ADD("THAT");
   LINES.ADD("ARRAYS");
   LINES.ADD("ARE");
   LINES.ADD("A");
   LINES.ADD("VERY");
   LINES.ADD("CONVENIENT");
   LINES.ADD("WAY");
   LINES.ADD("OF");
   LINES.ADD("STORING");
   LINES.ADD("SIMPLE");
   LINES.ADD("VALUES");
   LINES.ADD("AND");
   LINES.ADD("REFERENCES");
   LINES.ADD("TO");
   LINES.ADD("MORE");
   LINES.ADD("COMPLEX");
   LINES.ADD("CLASS");
   LINES.ADD("OBJECTS");
   LINES.ADD("IN");
   LINES.ADD("AN");
   LINES.ADD("ORDERED");
   LINES.ADD("LIST");
   LINES.ADD(".");

   FOR I := 1 STEP 1 UNTIL LINES.SIZE DO
   BEGIN
     OUTINT(I, 0); OUTTEXT(": ");
     OUTTEXT(LINES.GET(I)); OUTIMAGE;
   END;


   REALS :- NEW REALARRAYLIST;
   FOR I := 1 STEP 1 UNTIL 10 DO
     REALS.ADD(I * I);

   FOR I := 1 STEP 1 UNTIL REALS.SIZE DO
   BEGIN
     OUTINT(I, 4); OUTTEXT(": ");
     OUTFIX(REALS.GET(I),2,10); OUTIMAGE;
   END;

   FOR I := REALS.SIZE STEP - 2 UNTIL 1 DO
     REALS.REMOVE(I);

   FOR I := 1 STEP 1 UNTIL REALS.SIZE DO
   BEGIN
     OUTINT(I, 4); OUTTEXT(": ");
     OUTFIX(REALS.GET(I),2,10); OUTIMAGE;
   END;

END;