Re: [PATCH] Add :noweb-prefix and :noweb-trans babel header arguments

[Sébastien Miquel]

Hi,

Ihor Radchenko writes:

> Can you provide more concrete examples?
>
> > Some drawbacks:
> >   + doesn't work for all languages (does work for LaTeX)
> >       
> Which languages do not work?
>     
    Most languages do not work. Using your
      proposed solution, what I'm
      trying to do is
      
      #+name:_javascript_-header
      #+begin_src _javascript_ :tangle no
      some _javascript_, with \ and " to be escaped
      #+end_src
      
      #+name: string-escape
      #+begin_src emacs-lisp :var str="" :tangle no
      (prin1-to-string (string-trim-right str))
      #+end_src
      
      #+begin_src emacs-lisp :noweb yes :tangle yes
      (setq _javascript_-header
      <<string-escape(str=_javascript_-header)>>)
      #+end_src
      
      If you replace _javascript_ with latex, it happens to work, because
      when
      org executes a latex block, it prints its content.
      
      The goal is to tangle to some lisp code whose purpose is to
      generate
      LaTeX/_javascript_ code. Quite niche admittedly, though as you
      showed,
      it could also be used to string-escape documentation.

> >   + the tangle gets very noisy: not only are the result of execution
> >     printed in the echo buffer, but emacs visits the tangling buffer
> >     and moves the point to each block.
> >     Perhaps this is a bug that can be fixed.
> >       
> Did you try to play with :results header argument to disable messages?
> What exactly went unexpected?
>     
    
      I did. I might have missed something, but no combination of
      :results
      argument to both the latex block and the string-escape block
      silences
      the tangle (except for :results none, which doesn't tangle the
      content
      of the block). During tangle, the contents of the latex block are
      displayed (shortly) in the echo buffer (check *Messages*), and the
      point very briefly moves to the latex block. This isn't very
      noticeable with a single block.
> >   + src block execution also resets the noweb cache, slowing down
> >     tangle, though I have not tried to measure the effect.
> >       
> I am not sure what you are referring to here. Can you elaborate?
>

Lines 2892-2893 of (my) ob-core.el, in org-babel-expand-noweb-references:

>              ;;
>           Evaluation can potentially modify the buffer
>                        ;; and invalidate the cache: reset it.
      
        Regards,

-- 
Sébastien Miquel