[Cuis-dev] #valueEnsured return value

[Jaromir Matas]

Hi Hernan,
Thanks for your msg. I’m AFK so briefly: At least one critical use of valueEnsured (or [] ensure: aBlock) is in #terminate. We need to make sure the receiver is evaluated even if the process is terminated. Replacing it with #value will show you which test will fail :)

Yes, it may be understood as a mere shortcut as you wrote but I’m thinking it may as well get another semantics, which is: Evaluate the receiver no matter what and return the block’s return value. In terminate I don’t need the return value but in general it may make sense.

Any opinions welcome; although I’m aware this has rather rare use :)
Thanks again,
Jaromir

From: Hernán Wilkinson<mailto:hernan.wilkinson at 10pines.com>
Sent: Monday, February 27, 2023 13:18
To: Discussion of Cuis Smalltalk<mailto:cuis-dev at lists.cuis.st>; Martin McClure<mailto:martin at hand2mouse.com>
Cc: juan at cuis.st<mailto:juan at cuis.st>; Jaromir Matas<mailto:mail at jaromir.net>
Subject: Re: [Cuis-dev] #valueEnsured return value

hmmm I'm not sure it is a good idea because it goes against the expected return value of #ensure:
I mean, #valueEnsured is just a shortcut for [] ensure: [...], and #ensure: returns the return value of evaluating the receiver block, not the parameter block. The receiver block is [] so it should return nil ([] value).
Currently it is not returning nil because it is implemented like this:
[] ensure: self
and it should be:
^[] ensure: self

Now I'm thinking... I do not understand the need for #valueEnsured, why not just send #value to the block? What is the difference?
I see that #ensure: sends the message #valueNoContextSwitch instead of #value, why not sending #valueNoContextSwitch instead of #valueEnsured then?
I see that #valueEnsured was suggested by @Martin McClure<mailto:martin at hand2mouse.com> , Martin, could you explain the need for this message? Thank you!!

And now, because I'm inconsistent (that is, human :-) ), I'm not sure #valueEnsured has to keep the semantics of the return value of #ensure:, it could not if there is a need for what you are suggesting.
Anyway, I'd like to understand why #valueEnsured is needed.

Cheers!
Hernan.



On Sun, Feb 26, 2023 at 8:34 AM Jaromir Matas via Cuis-dev <cuis-dev at lists.cuis.st<mailto:cuis-dev at lists.cuis.st>> wrote:
Hi Juan, all,

I’d expect this example return 1 instead of a block (for general usage); what do you think?

[1] valueEnsured

Enclosed is a suggestion how to make it return 1.

Best,
Jaromir


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Jaromír Matas

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Hernán Wilkinson
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