[racket] why is the comparimng always false

Do pay attention to Vcat? and VCham? 

On Jun 29, 2012, at 4:12 PM, Roelof Wobben wrote:

> 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
>> 
>> 
> 
>