[Cuis-dev] reflection and questionable tab completion

[Mark Volkmann]

Thanks so much for explaining all of that!
What is the source of the blue messages? For example, what does it think
that `Smalltalk packages` represents if not a supported message?
What's the value in tab completion showing them if they aren't really
supported messages?

On Fri, Jun 14, 2024 at 12:43 PM Hernán Wilkinson <
hernan.wilkinson at 10pines.com> wrote:

> Hi Mark,
>  Smalltalk is a dynamically typed language, therefore the autocompletion
> tries to do its best due to the lack of type info.
>  For sure you noticed that some selectors that the autocomplete shows are
> in black and some are in blue. The ones in black are the ones that for sure
> the receiver of that message will answer, the ones in blue are the ones
> that the autocomplete does not know.
>  In your example, the selector packages is in blue because Smalltalk is an
> object whose type is well known by the environment and it will not answer
> that message. (Please do not confuse Smalltalk the language/environment
> with Smalltalk the object)
>  Just to clarify, Smalltalk is a global var that references an object
> instance of SystemDictionary, if you write "Smalltalk " (without the
> quotes) and press tab (*), the autocompletion will show you all the
> messages that Smalltalk will answer for sure. If you press "p" it will show
> you all the selectors that start with p, but if you press "pa" you will see
> they are in blue, that means that Smalltalk will not answer those messages.
>  Inferring what messages Smalltalk will answer is simple due to what I
> said in the previous paragraph, but most of the cases are not like that.
> For example, if you have the method "m1: something", what is the type of
> "something"? how can we infer the messages it will answer? There are many
> techniques, for example type inference (but it is slow and not "complete"),
> another is something we implemented in Cuis called "LivedTyping" where
> types of variables are collected dynamically and that info is used in all
> the tools, specially in the autocompletion.
>  The UX with LiveTyping is completely different because it is like having
> tools of a statically typed language but in a dynamically typed one. If you
> want to try it, download CuisUniversity from
> https://sites.google.com/view/cuis-university/descargas?authuser=0 that
> has LiveTyping installed. (The site is in Spanish, but you will understand
> :-) ).
>
>  I hope I answered your question, it is an interesting topic :-) If you
> have questions let me know.
>
> Cheers!
> Hernan.
>
> (*) For the autocompletion to open when you press tab this preference must
> be set:
> Preferences name: #spaceTabOpensAutoCompletion category: #gui value: true.
>
>
>
> On Fri, Jun 14, 2024 at 2:14 PM Mark Volkmann via Cuis-dev <
> cuis-dev at lists.cuis.st> wrote:
>
>> I'm learning about reflection in Smalltalk and trying out a bunch of
>> related methods. When I enter Smalltalk and part of a message name in a
>> Workspace and press the tab key I get lots of suggested completions. But
>> many of them give me MessageNotUnderstood when I "Print it". For example:
>>
>> Smalltalk packages
>>
>> Why would it suggest completions that aren't really implemented?
>>
>> --
>> R. Mark Volkmann
>> Object Computing, Inc.
>> --
>> Cuis-dev mailing list
>> Cuis-dev at lists.cuis.st
>> https://lists.cuis.st/mailman/listinfo/cuis-dev
>>
>
>
> --
>
> *Hernán WilkinsonAgile Software Development, Teaching & Coaching*
> *Phone: +54-011*-4893-2057
> *Twitter: @HernanWilkinson*
> *site: http://www.10Pines.com <http://www.10pines.com/>*
> Address: Alem 896, Floor 6, Buenos Aires, Argentina
>


-- 
R. Mark Volkmann
Object Computing, Inc.
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