I know.
As I understand it Vanimal is the world which can exist of a Vcat or a
Vcham.
The problem is that I cannot know which one it is and if don't do a
define-struct Vanimal () I cannot check if the make the right world.
I will reread the chapter how to solve this.
Roelof
Op 29-6-2012 21:47, Matthias Felleisen schreef:
On Jun 29, 2012, at 3:14 PM, Roelof Wobben wrote:
; Te gebruiken structs
; Design a world program that works with both cats and chameleons:
; A VAnimal is either
; – a VCat
; – a VCham
(define-struct Vanimal (Vchat Vcham))
Please re-read the chapter. The above is completely wrong.
EITHER a VAnimal is one of two things
OR it is a combination of two things.
You can't have it both ways. -- Matthias
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