[Cuis-dev] Parser gets confused when using $| in binary selectors

Luciano Notarfrancesco luchiano at gmail.com
Fri May 13 07:37:52 PDT 2022


Sounds good to me, but not a requirement for my use case, if you think it
would complicate the parser you don’t need to do it (at least not for me).

On Fri, 13 May 2022 at 9:31 PM Juan Vuletich <JuanVuletich at zoho.com> wrote:

> I'm pretty sure I can tweak the parser to treat specially $- as last char
> of a binary selector, so that
>
> 1 at -2 creates a Point.
> 1 @ -2 also creates a Point.
> 1 @- 2 (note the space between - and 2) sends #@-, whatever that might
> mean.
>
> I know it wouldn't be strictly ANSI, but that shouldn't be too important.
>
> Do you folks think this would be reasonable behavior?
>
> Thanks,
>
>
> On 5/13/2022 11:07 AM, Luciano Notarfrancesco via Cuis-dev wrote:
>
> Can you think of other characters that could be problematic when allowing
> them in binary selectors? I don’t use selectors ending with $-, and I agree
> that the original behavior is more convenient and intuitive. The only
> disadvantage of keeping the original behavior for this case would be not
> being ANSI compliant, not a problem for me.
>
> On Fri, 13 May 2022 at 8:58 PM Luciano Notarfrancesco <luchiano at gmail.com>
> wrote:
>
> Personally I don’t mind if we decide to make an exception for the special
> case of $-, but only for that character, because I want to have more
> options available for binary operators (for example with $|).
>
> On Fri, 13 May 2022 at 8:53 PM Hernan Wilkinson <
> hernan.wilkinson at 10pines.com> wrote:
>
> Even more... this change makes things like: 1*-2 or 1/-2 or 1//-2 or 1+-2,
> etc etc etc to generate an error.
> I think it does not make sense.... any common programmer will expect 1*-2
> to return -2 and not an error.
> I think we should get back to the previous behavior.
>
> What do you think?
>
> Hernan.
>
> On Fri, May 13, 2022 at 10:34 AM Hernan Wilkinson <
> hernan.wilkinson at 10pines.com> wrote:
>
> Hi all!
>  I'm just wondering why you guys think that having @- as a unary selector
> is better than interpreting it as valid for a negative y of a point...
>  I mean, it is much more common to write 1 at -1 as a point whose y is -1
> than to use @- as a selector...
>  Newcomers will have bit time problems to understand why 1 at -1 does not
> generate a point with a -1 as the y, unless the @- message is implemented
> in Point to create a point with the negation of the parameter which is for
> me an unnecessary indirection...
>  I mean, what other class is going to implement a message such as @- ?
>  It seems to me more useful the behavior we had previous to this change.
>
> Hernan.
>
>
> On Fri, May 13, 2022 at 9:52 AM Luciano Notarfrancesco via Cuis-dev <
> cuis-dev at lists.cuis.st> wrote:
>
> If you don't mind, I think these printOns look better (either one)
>
> On Fri, May 13, 2022 at 2:36 AM Luciano Notarfrancesco <luchiano at gmail.com>
> wrote:
>
> Oh, great, thanks! I was just thinking that “1@(-1)” could have been a
> better choice for the fix, and that maybe we should have a preference to
> avoid overwriting timestamp and other people’s initials when we do trivial
> changes like this.
>
>
> On Fri, 13 May 2022 at 3:41 AM Juan Vuletich <JuanVuletich at zoho.com>
> wrote:
>
> Thanks Folks!
>
> Luciano, I just pushed your changes. I also found an instance of '\\-'
> that I fixed too. There are several changes required for optional packages
> in the Cuis-Smalltalk organization. Will push them tomorrow.
>
> WRT to Decompiler, decompiled code is actually OK, with a space after
> binary selectors. What was wrong was the #storeString of literal Points.
> Fixed Point>>#printOn: for that. Now DecompilerTests pass.
>
> Cheers!
>
>
> On 5/9/2022 3:21 PM, Luciano Notarfrancesco via Cuis-dev wrote:
>
> Martin,
> Thanks for the very detailed explanation! I went ahead and replaced '@-'
> with '@ -' in the image and the tests. There are still 10 tests producing
> errors because the decompiler decompiles it without the space, tho.
>
>
> On Mon, May 9, 2022 at 5:04 PM Martin McClure <martin at hand2mouse.com>
> wrote:
>
> The ANSI Smalltalk grammar says that "@-" should be a valid binary
> selector, and would require whitespace in "1@ -1" to interpret the
> argument as a literal negative one.
>
> The Blue Book grammar, though, does not allow "@-" as a binary selector.
> The Blue Book grammar, as printed, also does not allow "," as a binary
> selector, even though that was clearly used as a binary selector in
> Smalltalk-80. The Blue Book grammar also does not talk about whitespace at
> all, even though that is clearly required in some places, so the Blue Book
> is a bit fuzzier than one would want as a grammar reference.
>
> Going with ANSI-like grammar and putting a space in expressions like "1 @-
> 1" makes more sense to me. Allows more valid selectors, and the code is
> more readable with the whitespace.
>
> Regards,
> -Martin
>
> On 5/9/22 03:48, Luciano Notarfrancesco via Cuis-dev wrote:
>
> After this change '1 at -1' is parsed as a binary message #@-, and this
> causes some base image tests to fail. Should we add a space between @ and
> -1 or should we fix the parser?
>
> On Fri, May 6, 2022 at 1:56 PM Luciano Notarfrancesco <luchiano at gmail.com>
> wrote:
>
> That was quick. Thanks a lot!
>
> On Fri, 6 May 2022 at 8:55 PM Juan Vuletich <JuanVuletich at zoho.com> wrote:
>
> On 5/6/2022 10:48 AM, Luciano Notarfrancesco via Cuis-dev wrote:
>
> I’m not sure I was clear, I meant a method implementing those messages,
> not sending those messages.
>
> On Fri, 6 May 2022 at 1:22 PM Luciano Notarfrancesco <luchiano at gmail.com>
> wrote:
>
> I’m getting “Argument name expected” when trying to compile a method with
> selector <|. On the other hand, |>, | and || all compile fine as binary
> selectors, but || breaks syntax highlighting.
>
>
> Sure. Fixes at GitHub now.
>
> A small detail: Now an empty temporal declaration `||` is parsed as a
> binary selector, and therefore marked as invalid. Not a big deal. We'd just
> remove any such.
>
> Cheers,
>
> --
> Juan Vuletichwww.cuis-smalltalk.orghttps://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Devhttps://github.com/jvuletichhttps://www.linkedin.com/in/juan-vuletich-75611b3https://independent.academia.edu/JuanVuletichhttps://www.researchgate.net/profile/Juan-Vuletichhttps://patents.justia.com/inventor/juan-manuel-vuletichhttps://twitter.com/JuanVuletich
>
>
>
>
>
> --
> Juan Vuletichwww.cuis-smalltalk.orghttps://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Devhttps://github.com/jvuletichhttps://www.linkedin.com/in/juan-vuletich-75611b3https://independent.academia.edu/JuanVuletichhttps://www.researchgate.net/profile/Juan-Vuletichhttps://patents.justia.com/inventor/juan-manuel-vuletichhttps://twitter.com/JuanVuletich
>
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>
>
>
> --
> <https://10pines.com/> Hernán Wilkinson Software Developer & Coach
>
> Alem 896, Floor 6, Buenos Aires, Argentina
>
> +54 11 6091 3125
>
> @HernanWilkinson
>
>
>
> --
> <https://10pines.com/> Hernán Wilkinson Software Developer & Coach
>
> Alem 896, Floor 6, Buenos Aires, Argentina
>
> +54 11 6091 3125
>
> @HernanWilkinson
>
>
>
> --
> Juan Vuletichwww.cuis-smalltalk.orghttps://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Devhttps://github.com/jvuletichhttps://www.linkedin.com/in/juan-vuletich-75611b3https://independent.academia.edu/JuanVuletichhttps://www.researchgate.net/profile/Juan-Vuletichhttps://patents.justia.com/inventor/juan-manuel-vuletichhttps://twitter.com/JuanVuletich
>
>
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