13 lines
278 B
Common Lisp
13 lines
278 B
Common Lisp
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(defclass circle ()
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((radius :initarg :radius
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:initform 1.0
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:type number
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:reader radius)))
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(defmethod area ((shape circle))
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(* pi (expt (radius shape) 2)))
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> (defvar *c* (make-instance 'circle :radius 2))
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> (area *c*)
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12.566370614359172d0
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