cyclic looping with [0 == object] whileFalse: [object := object
bonzini at gnu.org
Tue Nov 6 15:37:24 UTC 2007
> However given you are doing message sends, block evaluations etc in
> allInstancesDo:. Then *MILLIONS* of bytecodes and 100 of thousands of
> method invocations run
> to do the same task. Thus in a simple loop iterating over an object and
> doing a message send to ask them if they are a Morph is *way faster*
Unfortunately, something like this would also be slower than #nextObject:
Morph withAllSubclassesDo: [ :each |
inst _ each someInstance.
[inst == nil] whileFalse:
[next _ inst nextInstance.
inst removeProperty: #undoGrabCommand.
inst _ next]
because of the *huge* amount of Morph subclasses in the image. You
are walking the object memory hundreds of times rather than one, and I
found out a few years ago (on a different computer) that using a Set (!)
and #nextObject is faster than using #nextInstance if you have about 20
subclasses (or more).
This would work for Rob however.
More information about the Squeak-dev