An example program

This program implements a simple Pair class. It uses the Util.WriteInt method of the FMCP compiler in order to produce output when executed.

MODULE FMCPTest;

TYPE
  Elem = EXTENSIBLE RECORD (ANYREC)
    x: INTEGER;
  END;

  ExtElem = RECORD (Elem)
    y: BOOLEAN;
  END;

  Pair = EXTENSIBLE RECORD (ANYREC)
    fst: Elem;
    snd: Elem;
  END;

PROCEDURE (IN this: Pair) SetFst (e: Elem): Pair, NEW, EXTENSIBLE;
BEGIN RETURN NEW Pair (fst = e, snd = this.snd) END SetFst;

BEGIN
  util.WriteInt(NEW Pair(fst = NEW Elem(x = 1), snd = NEW Elem(x =
  2)).SetFst(NEW ExtElem(y = TRUE, x = 1)).fst.x)
END FMCPTest.