[Cuis-dev] Feature #require: completion event or test?

[ken.dickey at whidbey.com]

On 2023-03-21 12:57, Alexandre Rousseau via Cuis-dev wrote:

> My point was the system complained that "MyTheme beCurrent " , scripted 
> after the loading of said packaged theme, was pointing to a non 
> existent class ... i.e., the loading was not complete when the 
> "beCurrent" message was sent.    Which makes the loading of packages 
> asynchronous, does it not?

Actually, not.  It is a processing time problem.

The code is first compiled as _a block_ and when that happens 
#ClassicTheme is undefined, so nil.

If you initially type
    Feature require: #'Theme-Themes'.
    ClassicTheme beCurrent.
into a workspace, you will see #ClassicTheme in RED because it is yet 
undefined.

If you select both lines and DoIt, you will get the #ClassicTheme 
undefined exception, but if you select the first line and DoIt, then you 
will note #ClassicTheme has turned BLUE as it is now defined.  You can 
select the 2nd line and DoIt, AOK.

Since you are sending a block of text to be compiled at one time, you 
have to deal with undefined values _at the time the text is compiled_.

The easy fix in this case is to compile-in the explicit code to do the 
lookup:
   Feature require: #'Theme-Themes'.
   (Smalltalk at: #ClassicTheme) beCurrent.

Note that I do not find this very intuitive either.

HTH,
-KenD