From: Alex Sassmannshausen <alex.sassmannshausen@gmail.com>
To: guile-user@gnu.org
Subject: Re: Lenses in Guile?
Date: Tue, 18 Feb 2020 15:04:10 +0100 [thread overview]
Message-ID: <87eeusng9x.fsf@gmail.com> (raw)
In-Reply-To: <e712767a-7ef5-1f94-f82d-94eec6a9cf32@posteo.de>
Heya,
Zelphir Kaltstahl <zelphirkaltstahl@posteo.de> writes:
> Hi!
>
> This reminds me of something: Is there something like
> https://docs.racket-lang.org/lens/index.html for Guile? Or perhaps an
> easy to understand tutorial on implementing it?
Check out https://gitlab.com/a-sassmannshausen/guile-lens
It's an implementation I did for fun a while ago. Can't remember how
faithfully it implements lenses as compared with racket's…
Best wishes,
Alex
>
> Regards,
> Zelphir
>
> On 2/18/20 2:38 PM, Christopher Lam wrote:
>> A bit late, and perhaps not as sophisticated as some bigger modules here.
>>
>> Two functions defined as follows: nested-alist-set! nested-alist-get at
>> https://github.com/Gnucash/gnucash/blob/1f83cfaf64d1cd3c8862b427dd043154f780a772/gnucash/report/html-chart.scm#L37
>>
>> Consider a nested alist describing unix file system
>> (define lst
>> (list
>> (cons 'usr (list
>> (cons 'bin "binary files")
>> (cons 'games "g4m3s")
>> (cons 'include (list
>> (cons 'guile (list
>> (cons '2.2 "old")))
>> (cons 'linux "da best")))))))
>>
>> We can access a leaf node via (nested-alist-get lst '(usr include linux))
>> --> "da best", and set a leaf node via (nested-alist-set! lst '(usr include
>> python) "boo"). This is probably easy to seasoned schemers, but still a
>> nice pair of functions to use in modifying nested alists before conversion
>> into json.
>>
>> On Mon, 17 Feb 2020 at 09:16, Ludovic Courtès <ludo@gnu.org> wrote:
>>
>>> Hi!
>>>
>>> Ricardo Wurmus <rekado@elephly.net> skribis:
>>>
>>>> What do you think about adding these things to
>>>> https://notabug.org/cwebber/guile-webutils/ ? This was once intended to
>>>> be a collection of useful tools that come in handy when writing web
>>>> applications.
>>> I didn’t know about guile-webutils but consolidating Web tools in this
>>> package sounds like a great idea!
>>>
>>> Ludo’.
>>>
>>>
next prev parent reply other threads:[~2020-02-18 14:04 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-16 14:56 Happy birthday, Guile! Ludovic Courtès
2020-02-16 16:20 ` Linus Björnstam
2020-02-16 18:36 ` Arun Isaac
2020-02-16 21:08 ` sirgazil
2020-02-16 19:14 ` Roel Janssen
2020-02-16 19:30 ` Ricardo Wurmus
2020-02-17 9:16 ` Ludovic Courtès
2020-02-18 13:38 ` Christopher Lam
2020-02-18 13:44 ` Lenses in Guile? Zelphir Kaltstahl
2020-02-18 14:04 ` Alex Sassmannshausen [this message]
2020-02-19 14:27 ` Zelphir Kaltstahl
2020-02-23 17:00 ` Ludovic Courtès
2020-02-16 21:13 ` Happy birthday, Guile! Mike Gran
2020-02-16 21:34 ` sirgazil
2020-02-16 21:54 ` Ricardo Wurmus
2020-02-16 22:14 ` Jeremy Korwin-Zmijowski
2020-02-16 23:51 ` potluck; " Arne Babenhauserheide
2020-02-17 0:10 ` Happy birthday, Guile! - grid printing Zelphir Kaltstahl
2020-02-17 8:01 ` Linus Björnstam
2020-02-17 14:58 ` Zelphir Kaltstahl
2020-02-17 16:21 ` Linus Björnstam
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