17 lines
411 B
Racket
17 lines
411 B
Racket
;#lang racket
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(define point%
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(class object%
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(super-new)
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(init-field x y)
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(define/public (clone) (new this% [x x] [y y]))
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(define/public (to-list) (list this% x y))))
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(define point/color%
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(class point%
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(super-new)
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(inherit-field x y)
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(init-field color)
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(define/override (clone) (new this% [x x] [y y] [color color]))
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(define/override (to-list) (list this% x y color))))
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