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From: "Linus Björnstam" <linus.internet@fastmail.se>
To: "Maxime Devos" <maximedevos@telenet.be>,
	"Zelphir Kaltstahl" <zelphirkaltstahl@posteo.de>
Cc: "Guile User" <guile-user@gnu.org>
Subject: Re: Macro for replacing a placeholder in an expression
Date: Fri, 05 Aug 2022 11:42:20 +0200	[thread overview]
Message-ID: <18fd1f47-0fac-420b-bb4f-37eddaa5315f@www.fastmail.com> (raw)
In-Reply-To: <51f4c121-6143-345e-43d4-6f97e0be8501@telenet.be>

I wrote this, which does a tree fold over a sexp:

https://hg.sr.ht/~bjoli/megacut/browse/readme.txt?rev=tip

It is unhygienic currently, and I will probably never change because I only use it at the repl. 

The code is really just a syntax-case version of the fast and efficient flatten algorithm, but without flattening. 

-- 
  Linus Björnstam

On Sat, 30 Jul 2022, at 23:13, Maxime Devos wrote:
> On 30-07-2022 17:42, Zelphir Kaltstahl wrote:
>>
>> Does this mean, that recursive application of a macro inside a macro 
>> is impossible? To expand to subforms being the same macro again and 
>> this way transform a whole tree of s-expressions?
>>
> You can have recursive macros, see e.g. the let^ macro at 
> <https://git.gnunet.org/gnunet-scheme.git/tree/gnu/gnunet/utils/hat-let.scm>.
>
> However, I do not see a way to implement recursivity the same way for 
> your macro.
>
> Greetings,
> Maxime.
>
>
> Attachments:
> * OpenPGP_0x49E3EE22191725EE.asc
> * OpenPGP_signature



  reply	other threads:[~2022-08-05  9:42 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-27 23:57 Macro for replacing a placeholder in an expression Zelphir Kaltstahl
2022-07-28  0:55 ` Maxime Devos
2022-07-28 10:23   ` Zelphir Kaltstahl
2022-07-28 10:28     ` Maxime Devos
2022-07-30 15:42     ` Zelphir Kaltstahl
2022-07-30 20:44       ` Maxime Devos
2022-07-30 21:10         ` Maxime Devos
2022-07-30 21:13       ` Maxime Devos
2022-08-05  9:42         ` Linus Björnstam [this message]
2022-08-06 14:28           ` Zelphir Kaltstahl
2022-07-28  1:04 ` Maxime Devos
2022-07-28  8:39   ` Zelphir Kaltstahl
2022-07-28  9:48     ` Maxime Devos
2022-07-28 11:26       ` Zelphir Kaltstahl

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