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Randal L. Schwartz wrote:
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<pre wrap="">"Ben" == Ben Coman <a class="moz-txt-link-rfc2396E" href="mailto:btc@openInWorld.com"><btc@openInWorld.com></a> writes:
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Ben> doh! <smacks-head> funny how it works itself out when you step away for a
Ben> while - this works fine...
Ben> B class >> relations
Ben> (self == B)
Ben> ifTrue: [ ^ { E-> #addE. } ]
Ben> ifFalse: [ ^ {} ]
Ben> but I still wonder if it is the right approach
Without further analysis, or description of the problem you're trying to
solve, this already looks far too fragile for me.
For one, it fails the "null subclass" test. You should always be able
to subclass a class, putting no methods in the subclass, and the
subclass and superclass objects would be completely interchangeable.
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I've been taking my time to wrap my head around your comment. It makes
complete sense when thinking about the use of the object model.
However (if you can refer to the attached diagram showing one
association and one inheritance relationship) what I am trying to work
out is whether that applies as strongly one level up at the meta /
class description. <br>
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If ConductingEquipment is a null-subclass then at the instance/model
level it could be completely interchanged with Equipment because the
association is inherited. However at the meta / class-description
level (ie storing the data to be able to redraw that diagram)
ConductingEquipment and Equipment seem not interchangable since no
direct line exists between ConductingEquipment to EquipmentContainer.<br>
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I'll continue to muse on that. Thanks for you reply.<br>
cheers -ben<br>
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