Dictionary Associations can be directly modified, leading to bizarre KeyNotFound errors

[sdasda7777]

Bug description I was seriously confused for the last two hours or so, because every time I did dict at: string on my Dictionaries, I would get a KeyNotFound error. However I could see the key was in there, and even dict keys includes: string would come back as True. Following are pictures that show the two strings byte per byte.

The reason was that I was doing dict associationsDo: [ :pair | pair key: (fun (pair key))], which changed the key, but I assume it didn't change where it was in the underlying tree structure, or something like that.

In short, I don't think keys should be exposed to modification in this way. I would have never figured it out if I didn't have some knowlege of how Dictionaries usually work, which I think common person doesn't. If you need to know how abstraction works under the hood to use it properly, that's a bad abstraction.

To Reproduce Create a dictionary, iterate associations, directly modify some keys. The tree will be built on outdated information, and you will only find anything if you're very lucky.

[welcome[bot]]

Thanks for opening your first issue! Please check the CONTRIBUTING documents for some tips about which information should be provided. You can find information of how to do a Pull Request here: https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo

GitHub

Contribute a fix to Pharo

Pharo is a dynamic reflective pure object-oriented language supporting live programming inspired by Smalltalk. - pharo-project/pharo

[svenvc]

Hi,

Thanks for the feedback.

You are correct but it has always been like that and it unlikely to change soon.

Yes, associations are part of the internal structure of the dictionary and should never be changed in place.

Maybe the key could be made readonly once the association is created, I am not sure that is possible at that granularity.

Sven