Re: [xml-dev] Instances changing their type [was:Discover data patternso

[Manos Batsis <manos_lists@geekologue.com>]

Michael Kay wrote:
> Of course all problems in computing can be solved by adding a layer of
> indirection. You can design a wrapper object that implements the interface
> and delegates all the work to either an ArrayList or a LinkedList. This
> wrapper object is the only object to know about the implementation object so
> only one place has to change when the implementation changes. But it would
> be nice if this were built into the language, not something you have to
> program yourself. Apart from anything else, forwarding all the method
> invocations is expensive.


Just for the discussion (I've seen Saxon's code ;-), a more efficient 
method would be to only use the List interface and eliminate all 
implementation class references, including initial creation, using a 
"dynamic" Factory. That Factrory could offer, besides some initial 
configuration via property file or whatnot, a runtime method to change 
the implementation at runtime through a console etc.

Cheers,

Manos