Idiom or method for determining where in the class hierarchy an object fits

I have a class hierachy that looks like this

class A

end

class B < A

end

class C < A

end

class D < B

end

class E < C

end

class F < B

end

Now class B has a method that expects either members of class D or E
or Fas a parameter but needs to do something different based upon the
whether the parameter is a subclass of B or a subclass of C.
I could check to see if it was D or F as opposed to B but that would
mean when I added class G<B…end I’d have to go back and touch B.
Is there a way to ask an object if it is descended from a particular
class? I suppose I could add a method to B and test for the presence
of that method in the parameter objects but that feels ucky.

Thanks

Collins

On Aug 26, 2010, at 2:15 PM, Collins wrote:

class C < A

class? I suppose I could add a method to B and test for the presence
of that method in the parameter objects but that feels ucky.

Thanks

Collins

You could try kind_of? e.g.

o = F.new
=> #<F:0x00000100a74a30>

o.kind_of?(A)
=> true

o.kind_of?(B)
=> true

o.kind_of?©
=> false

etc.

Hope this helps,

Mike

Mike S. [email protected]
http://www.stok.ca/~mike/

The “`Stok’ disclaimers” apply.

On Aug 26, 2:30 pm, Mike S. [email protected] wrote:

end

Now class B has a method that expects either members of class D or E
Collins
=> false

The “`Stok’ disclaimers” apply.

Thank you! I was only aware of instance_of? This is exactly what I
was hoping to find…

Thanks again

Collins

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