# 25jun07abu# (c) Software Lab. Alexander Burger# The Shape base class(class +Shape)# x y(dm T (X Y)   (=: x X)   (=: y Y) )(dm move> (DX DY)   (inc (:: x) DX)   (inc (:: y) DY) )# The Rectangle class(class +Rectangle +Shape)# dx dy(dm T (X Y DX DY)   (super X Y)   (=: dx DX)   (=: dy DY) )(dm area> ()   (* (: dx) (: dy)) )(dm perimeter> ()   (* 2 (+ (: dx) (: dy))) )(dm draw> ()   (drawRect (: x) (: y) (: dx) (: dy)) ) # Hypothetical function 'drawRect'# The Circle class(class +Circle +Shape)# r(dm T (X Y R)   (super X Y)   (=: r R) )(dm area> ()   (*/ (: r) (: r) 31415927 10000000) )(dm perimeter> ()   (*/ 2 (: r) 31415927 10000000) )(dm draw> ()   (drawCircle (: x) (: y) (: r)) )       # Hypothetical function 'drawCircle'# The Fixed prefix class(class +Fixed)(dm move> (DX DY))  # A do-nothing method# vi:et:ts=3:sw=3