emacs-orgmode@gnu.org archives
 help / color / mirror / code / Atom feed

From: Rasmus <rasmus@gmx.us>
To: emacs-orgmode@gnu.org
Cc: aaronecay@gmail.com
Subject: Re: [BUG] Noweb reference eval syntax does not work
Date: Sun, 08 May 2016 14:57:29 +0200	[thread overview]
Message-ID: <87futs3dxi.fsf@gmx.us> (raw)
In-Reply-To: 87shxsaojc.fsf@saiph.selenimh

Hi,

Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> fm4d <m@fm4d.net> writes:
>
>> The noweb reference syntax that should insert results of
>> evaluation of src block itself instead of src block as
>> described in `org-babel-expand-noweb-reference` does not
>> seems to work.
>>
>>
>> Code for replication:
>>
>> * Assign 
>>
>> First we assign abc:
>>
>> #+begin_src python :noweb-ref assign_abc
>> abc = "abc" + "def"
>> #+end_src
>>
>> * Use
>>
>> Then we use it in a function:
>>
>> #+begin_src python :noweb tangle :tangle noweb-test.py
>> def x():
>>   <<assign_abc>>
>>   return abc
>>
>> print(x())
>> #+end_src
>>
>>
>> <<assign_abc>> does work, <assign_abc()> fails with this error:
>>
>> (error "Reference ‘assign_abc’ not found in this buffer")
>>   signal(error ("Reference ‘assign_abc’ not found in this buffer"))
>>   error("Reference `%s' not found in this buffer" "assign_abc")
>>   org-babel-ref-resolve("assign_abc()")
>>   ...
>>
>>
>> I am not sure if this is a bug or I am doing something wrong,
>> the documentation on this feature is not very comprehensive.
>
> I just discovered the :noweb-ref parameter.

I have used :noweb yes in the past, but it seems :noweb-ref can be
replaced by name in at least the single blog case:

    #+name: data
    #+BEGIN_SRC R
      set.seed(42)
      df1 <- data.frame(x=rnorm(10), y=rnorm(10))
    #+END_SRC

    #+BEGIN_SRC R :noweb yes
    <<data>>
    colMeans(df1)
    #+END_SRC

As you mention, we’d loose the ability to chain together multiple blocks.
I reckon they are meaningfully the same language, so I don’t see a loss.
The example shown in the manual also does not convince me of the
usefullness of this.

> It is redundant with #+NAME: keyword and slightly broken. Also it
> induces hacks like `org-babel-use-quick-and-dirty-noweb-expansion' to
> work-around its shortcomings. 
>
> Besides, it doesn't make much sense to add the same parameters to
> a bunch of blocks, so I find the syntax dubious.
>
> I understand it can be a handy shortcut for inserting multiple blocks,
> but, all in all, I tend to think it would be simpler to just remove the
> feature, along with `:noweb-sep' and
> `org-babel-use-quick-and-dirty-noweb-expansion'.

I’m happy to kill it off in Org-9.  I don’t know how widely the chaining
of blocks is used, though, and whether the fix is always as simple as
uniting the blocks.

> What do you, and others, think? Is NAME enough for noweb syntax, or is
> there a real need fo :noweb-ref?

I've put Aaron in carbon copy as he’s quite familiar with ob.

Rasmus

-- 
Governments should be afraid of their people

next prev parent reply	other threads:[~2016-05-08 12:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-05 21:39 [BUG] Noweb reference eval syntax does not work fm4d
2016-05-08  9:26 ` Nicolas Goaziou
2016-05-08 12:57   ` Rasmus [this message]
2016-05-08 16:32     ` Thomas S. Dye
2016-05-11 21:34       ` Nicolas Goaziou
2016-05-11 22:40         ` Samuel Wales
2016-05-11 23:19         ` Charles C. Berry
2016-05-12 23:35     ` Aaron Ecay
2016-05-15 22:40       ` Nicolas Goaziou
  -- strict thread matches above, loose matches on Subject: below --
2016-08-04 21:11 Karsten Schmidt
2016-08-05  2:25 ` Charles C. Berry

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=87futs3dxi.fsf@gmx.us \
    --to=rasmus@gmx.us \
    --cc=aaronecay@gmail.com \
    --cc=emacs-orgmode@gnu.org \
    /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

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).