Re: "Missing" libraries/concepts found in other languages/ecosystems?

[Zelphir Kaltstahl <zelphirkaltstahl@posteo.de>]

Hi all!

On 7/10/20 1:20 PM, Catonano wrote:
> Il giorno ven 10 lug 2020 alle ore 12:21 Chris Vine <vine35792468@gmail.com>
> ha scritto:
>
>> On Fri, 10 Jul 2020 10:49:37 +0200
>> Catonano <catonano@gmail.com> wrote:
>>> Il giorno mer 8 lug 2020 alle ore 20:22 Zelphir Kaltstahl <
>>> zelphirkaltstahl@gmail.com> ha scritto:
>>>
>>>> Hi Simen!
>>>>
>>>> On 7/8/20 6:00 PM, guile-user-request@gnu.org wrote:
>>>>> Hi, I'm new to scheme/lisp, so I'm trying to find out how to do
>>>>> things the "lisp
>>>>> way". On the other hand, I like things from other ecosystems too,
>>>>> and I'm having
>>>>> problems finding this for Guile. It might be because there's no
>>>>> need for it/I'm
>>>>> terrible at searching/nobody had the time yet, or something else.
>>>>>
>>>>> I've been trying to find implementations for https://reactivex.io
>>>>> without any
>>>>> luck. And I'm unable to find implementation of FP concepts as
>>>>> found in Haskell
>>>>> and other languages. Functor, Monad, lenses (and other helpers for
>>>>> working with
>>>>> immutable data).
>>>>>
>>>>> Does things like this exists, or is it better to use something
>>>>> else?
>>>>>
>>>>> Regards Simen
>>>> To what others already have written I will add:
>>>>
>>>> From time to time one can copy ideas from Racket or look at what exists
>>>> in Racket for solving a problem or seeing what the approach is.
>>>>
>>>> Catonano identified already the lack of examples in the Guile guide. I
>>>> fight with that myself, so I created a repository with examples.
>> Perhaps
>>>> I should somehow add them to the guide. I've not looked into how to do
>>>> that. Probably some commit in a repo somewhere for the guide:
>>>>
>>>> https://notabug.org/ZelphirKaltstahl/guile-examples
>>>>
>>>> Hope this can help!
>>>>
>>> Thank you, yes that helps
>>>
>>> In fact, it's a precious resource !
>>>
>>> I was especially delighted with the examples of using exceptions !
>>>
>>> I had so missed examples of those !
>>>
>>> As for the manual, very recently a mention of Guile Hall ended up being
>>> included in the manual
>>>
>>> The same could be done with your examples collection
>>>
>>> I also think that your collection could be mentioned by the Guile web
>> site,
>>> maybe in the "learn" section
>>>
>>> Here's the repo for the web site:
>>> https://git.savannah.gnu.org/cgit/guile/guile-web.git/
>>>
>>> a regular patch could do
>>>
>>> What do people think of mentioning this resource on the Guile web site ?
>> Whilst I don't have strong feelings, as a general approach I think it is
>> better to include additional examples (where needed) in the body of the
>> manual, which I think is generally well written.
>>
> As long as some examples are reachable from an officially sanctioned
> documentation source, I'm ok with that
>
> What I find problematic is the casualness in referring to bits scattered
> all around
>
> The web site was just an idea, the manual would be perfectly fine
>
> Also, at this level of detail what some find helpful others don't.  You
>> were delighted above with the exceptions example, whereas (if I read
>> the right one) I thought that that was one of the weaker ones.  It
>> concentrates on R6RS/R7RS exceptions and with-exception-handler rather
>> than with guile's much easier to use catch expression (for guile-2.2)
>> or (for guile-3.0) its beefed-up with-exception-handler and exception
>> objects.
>>
> Ah there has been a misunderstanding here
>
> I was convinced that the exceptions example was of the last layout for
> using exceptions reached recently in Guile 3.x
>
> If it's not, I agree it's less valuable
>
> But I think the author was just confused or led astray by the casualness of
> referring to scattered bits, I'm not blaming them
>
> I'd be grateful if anyone with enough understanding of the issue would
> contribute a proper example of how to use exceptions according to the last
> exceptions reorganization in Guile 3.x
>
> I would be happy to send a patch for the manual containing such example and
> a few words, as I did with the mention of Guile Hall
>
>
> with-exception-handler is a tricky beast and the example didn't deal
>> with the main case: most uses of exceptions involve handling them and
>> moving on with program execution from the point where the exception is
>> caught, and to do that using with-exception-handler instead of
>> guile's 'catch' form you have to have a call/ec helper (or with
>> guile-3.0 you can just set the #unwind argument to true).  Instead you
>> are left with the idea that you use continuable exceptions for that
>> (which while they do stop the program exiting are something different)
>> or the R6RS/R7RS guard form.
>>
> I'm not following you on this because I don't know enough of both the Guile
> new idea of how to use exceptions and the R6/7RS one
>
>
>> I am not trying to be critical here - I think examples are useful to
>> convey points and some of them were fine.  My point is more about venue.
>>
>  No, that's ok, that's why I asked
>
> In fact, should we end up with a proper example in the manual, that would
> be a positive outcome
>
> I'd say more, here
>
> I'd go systematically through all the examples in that repo and do a
> similar assessment if we can add it to the manual as is or if it needs
> refinement
>
> I can't do this on my own because in many cases I don't know enough to come
> up with valid examples myself
>
> But I'd be happy to prepare patches for the manual, given the right
> directions


I would be glad, if any non-optimal example was extended or updated by a
more knowledgeable person or I was told what I could improve in some
example. The examples in the repository are only, what I was able to
understand and I often find myself looking up, how to do something again.

If anyone wants to take any example and put it in the docs, go ahead.
Only don't think that my examples are the last word on how to do things.
Far from it!

About the exceptions thing: Aha! I should look into that again. I
thought the "conditions" thing was already pretty cool and useful. Once
an exception happens, you can react on it. I did not understand the
"call/ec helper" part, but perhaps I can understand it, when I check the
docs for the new exceptions in Guile 3.

I had another thought: Why do we not create this kind of so called
"awesome list" for Guile? There were some links in this discussion,
which might be a good fit on such a list and it is kind of informal,
easy to extend. Whenever someone asks for pointers, we could also
mention that list and perhaps they can find cool things in it. They
could see, that Guile is viable, because there are so many things people
do with Guile, or they could see their use case covered already.

Best regards,
Zelphir