I understand #basicAt:[put:] being in Object, but I never understood #at:[put:] being there. GNU Smalltalk: st> nil at: 1 Object: nil error: Invalid value nil: object not indexable In my Smalltalk, you get a DNU. In Squeak you get a debugger window with title Error: instances of UndefinedObject are not indexable The same for Boolean, Character, and Integer, except Squeak where (20 factorial at: 1) answers 0 (oh dear oh dear oh dear). In VW you get a "Subscript out of bounds" error, which is disappointing, as do true and $a, but a LargePositiveinteger gets #shouldNotImplement.
On Tue, 12 Mar 2019 at 15:28, Tim Mackinnon <tim@testit.works> wrote: > If you forget to initialise a variable which you thought was a Dictionary > - you get a confusing error message: "Error: only integers should be used > as indices” if you try an at:put: > > This is a consequence of having at:put: defined on Object (which is a bit > nasty) > > Should UndefinedObject at least override this and signal something a bit > more obvious? This is a common and easily done thing and we don't support > it very well. > I just did it in some code, and was scratching my head initially until I > read the stack properly and realised it was something much simpler than I > thought I had done. > > Any thoughts on this? >
