Re: AKClassHierarchy
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- Subject: Re: AKClassHierarchy
- From: Gavin Kistner <gavin@...>
- Date: 2006年2月11日 11:52:26 -0700
On Feb 11, 2006, at 11:42 AM, PA wrote:
* Does not currently support any sort of 'super' mechanism for
magically calling methods from an ancestor with the same name.
What about doing it explicitly instead of magically?
super.init( self )
In other words, you want the parent implementation (super.init) act
on the current instance (self).
That's what I have now, but you have to explicitly specify the parent
class:
Rectangle = AKClass:new( )
function Rectangle:initialize( inW, inH )
self.w = inW or 0
self.h = inH or 0
end
Square = AKClass:new( Rectangle )
function Square:initialize( inLength )
Rectangle.initialize( self, inLength, inLength )
end
UnitSquare = AKClass:new( Square )
function UnitSquare:initialize( )
Square.initialize( self, 1 )
end
I tried what you suggest (albeit with "self.class.superclass",
because I don't have a super property directly available to
instances), but it fails when you have more than one level involved:
function Square:initialize( inLength )
self.class.superclass.initialize( self, inLength, inLength )
end
function UnitSquare( inLength )
self.class.superclass.initialize( self, 1 )
end
The problem is that when the UnitSquare instance is passed to
Square's initializer, the self.class is still UnitSquare, which means
that Square's initializer will infinitely call itself. For more info
on this problem, see the second half of this post I made on the
comp.lang.ruby group last night:
http://groups.google.com/group/comp.lang.ruby/browse_frm/thread/
c3b22bf2d53bd68b/89525293809a02e3#89525293809a02e3