Andreas Raab wrote:

André Wendt wrote:

...

I just stumble upon this: Object>>#at:put: calls primitive:61. If that fails, the following lines read

index isInteger ifTrue: [self class isVariable ifTrue: [(index >= 1 and: [index <= self size]) ifTrue: [self errorImproperStore]

Why is it an improper store if the index is an integer, the receiver class is variable, and the index is within bounds? Someone please enlighten me...

Because it's the only failure mode that's left. It happens when you create non-pointer subclasses, for example:

Object variableWordSubclass: #MyWordArray instanceVariableNames: '' classVariableNames: '' poolDictionaries: '' category: 'Sample-Objects'

and now:

wa := MyWordArray new: 10. wa at: 1 put: 0. "works" wa at: 2 put: nil. "fails" wa at: 3 put: -1. "fails" wa at: 4 put: 16r100000000. "fails" wa at: 5 put: Smalltalk. "fails"

etc.

...

(If this is merely reporting "there was an error in the primitive although everything's alright", then I feel the message should be something other than "Improper store into indexable object".)

Think about this for a second. What possible other failure mode could there be in the at:put: primitive?

I guess you're right. It really *is* the only failure mode left.

Best, André