emacs-orgmode@gnu.org archives
 help / color / mirror / code / Atom feed
From: Ihor Radchenko <yantar92@gmail.com>
To: sebastien.miquel@posteo.eu
Cc: emacs-orgmode <emacs-orgmode@gnu.org>,
	Greg Minshall <minshall@umich.edu>
Subject: Re: [FR] Make :var foo=name-of-src-block assign the source block code instead of currently assigned result of evaluation (was: [PATCH] Add :noweb-prefix and :noweb-trans babel header arguments)
Date: Sat, 23 Jul 2022 12:52:12 +0800	[thread overview]
Message-ID: <87sfmsv3b7.fsf@localhost> (raw)
In-Reply-To: <635c8e99-ea37-f93a-4eab-e547d2c2ab61@posteo.eu>

Sébastien Miquel <sebastien.miquel@posteo.eu> writes:

> The uses are maybe too niche to warrant the breaking change. A syntax
> extension like
>   : var=block-id[]
> seems possible, even though brackets are already overloaded.

This sounds better. Using brackets will actually make a lot of sense.

Currently, we have roughly the following logic in the :var references:

- :var x=reference(<optional parameters>)
  will execute the reference and assign the returned value

- :var x=reference[<optional parameters>]
  will take the reference text representation, possibly process it
  according to the parameters, and return the processed text

  *this only works for tables*

- :var x=reference
  will perform some "default" action depending on the reference type.
  the action may be "execute" or "get text representation" for source
  blocks and others correspondingly.

Extending reference[...] syntax to all the element types will make
things consistent and allow future extensions if we decide to provide
"index" syntax for non-tables (code lines, function definitions?)

> One alternative is to only allow the syntax inside noweb brackets
> instead of generic variable arguments. I assume there'd be much less
> breakage. It would also makes sense to allow noweb references instead
> of block ids. We'd add support for
>   : <<babel-fn(var=noweb-ref)>>
> and <<babel-fn(var=block-id)>> would also insert the contents as a
> by-product.

This would still be a breaking change. And we will introduce
inconsistency between resolving noweb references and resolving :var
header args.

Moreover, resolving references is currently handled by the same code
inside :vars and noweb references. Changing this will complicate the
source code as well, IMHO increasing the maintenance burden too much.

> Do you have any example of use in mind, beyond my original one ?

For example, one may convert .el file commentary to Readme.org:

#+name: my-library
#+begin_src :tangle my-library.el
;; Commentary:
;; A lot of commentary
#+end_src

#+begin_src :exports results :var commentary=my-library[]
(convert-to-org-headlines commentary)
#+end_src

Best,
Ihor


  reply	other threads:[~2022-07-23  4:52 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-15 10:42 [PATCH] Add :noweb-prefix and :noweb-trans babel header arguments Sébastien Miquel
2022-04-28 13:45 ` Ihor Radchenko
2022-04-29 14:27   ` Sébastien Miquel
2022-04-30  6:05     ` Ihor Radchenko
2022-04-30  7:35       ` Sébastien Miquel
2022-04-30  8:41         ` Ihor Radchenko
2022-05-30 19:51       ` Sébastien Miquel
2022-05-31  5:14         ` Ihor Radchenko
2022-05-31  6:48           ` Sébastien Miquel
2022-07-16  8:57             ` [FR] Make :var foo=name-of-src-block assign the source block code instead of currently assigned result of evaluation (was: [PATCH] Add :noweb-prefix and :noweb-trans babel header arguments) Ihor Radchenko
2022-07-16 10:17               ` Greg Minshall
2022-07-16 10:45                 ` Ihor Radchenko
2022-07-16 14:31                   ` Greg Minshall
2022-07-17 17:39                   ` Sébastien Miquel
2022-07-23  4:52                     ` Ihor Radchenko [this message]
2022-08-29 17:39                       ` [PATCH] " Sébastien Miquel
2022-08-31  4:04                         ` Ihor Radchenko
2022-07-21 11:13             ` [PATCH] org-babel: Do not echo output of resolved noweb references Ihor Radchenko
2022-07-21 13:41               ` Sébastien Miquel
2022-08-22 12:01               ` Ihor Radchenko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.orgmode.org/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87sfmsv3b7.fsf@localhost \
    --to=yantar92@gmail.com \
    --cc=emacs-orgmode@gnu.org \
    --cc=minshall@umich.edu \
    --cc=sebastien.miquel@posteo.eu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).