On 11 February 2011 02:28, David T. Lewis <lewis@mail.msen.com> wrote:
We had a good deal of discussion earlier about adding Object>>is: with an inconclusive outcome: Â http://lists.squeakfoundation.org/pipermail/squeak-dev/2010-April/148501.htm...
Igor's original proposal is: Â http://lists.squeakfoundation.org/pipermail/squeak-dev/2009-June/136793.html
I have been tinkering around with Juan's SimpleMorphic in hopes of getting it running in Squeak alongside MVC and Morphic, and it would be convenient to have the default implementation of #is: in the image so I don't have to put it in a package override.
Just yesterday i had discussion about this with people in the lab. I can't say that i heard something new regarding this, and not saying that i'd like to resurrect the discussion. So, in short: there was no objection concerning getting rid of isXXX in favor of using #is: method. The only thing which still looks controversial is too simple default implementation which answers false. To my current opinion, Juan's variant is preferable. :) Yes. it should answer false and don't contain any extra logic , like trying to follow class hierarchy etc. Because it serves to replace isXXXX pattern, and not adding something new (i.e. more 'userful'). So, answering false for Object class fits well for this purpose. And of course solution to that problem is simple: - avoid writing code in style, which require isXXX tests and then branching. Nicely written code should use message dispatch instead. Too bad, we are not living in perfect world :)
Any strong objections?
-- Best regards, Igor Stasenko AKA sig.