Re: input data for babel blocks

[Charles Berry <ccberry@ucsd.edu>]

Alan Schmitt <alan.schmitt <at> polytechnique.org> writes:

> 
> Hi Charles,
> 
> ccberry <at> ucsd.edu writes:
> 
> > Lacking that, another alternative to the approach you have crafted is to
> > use elisp src blocks to set up the commands needed to create the 
> > objects,
> > and then place the results of executing the elisp src block in the src
> > block of your favored language using noweb, for example
> >
> > #+BEGIN_SRC mylang :noweb yes
> >   <<elisp-conversion-to-mylang("arg1","arg2")>>
> > #+END_SRC
> >  
> > might convert 'arg2' to an object of the desired type named 'arg1' in a 
> > 'mylang' src block.
> 
> This looks like a very powerful approach, but it's a bit beyond my
> understanding of babel (which is limited) and noweb (whose existence I
> just discovered after reading http://orgmode.org/manual/noweb.html).
> 

Sorry if it was a bit obtuse. The examples given by others seem to have 
helped. And I will give one more.

[deleted]

> If you have an example that uses different languages, I'd love to look
> at it. I'll then try to write an example for ocaml.
> 


Here is what I use for LaTeX thru elisp to R:



* Quote Blocks 

quote-blks takes two args:

- blk :: a string of comma separated src block names
- sep :: an optional separator for use when there is more than one
         block

I usually save it in a file and load it in with  
(org-babel-lob-ingest file). But you can copy and paste and the example 
below will still work.

#+name: quote-blks
#+BEGIN_SRC emacs-lisp :var blk="abc" :var sep="\"\n\""
    (save-excursion
      (replace-regexp-in-string "\"\"" ""
       (mapconcat
        (lambda (x) 
          (org-babel-goto-named-src-block x)
          (format "%S" (cadr  (org-babel-get-src-block-info  t))))
        (split-string blk "," t)
        sep)
       t t))
      
#+END_SRC


* example of use


The LaTeX here can be editted via C-c ' 
(i.e. org-edit-special --> org-edit-src-code).

#+name: lstuff
#+BEGIN_SRC latex :eval never :exports none
Here is a \backslash. And an unmatched quote: '.
#+END_SRC


Here is an example using it on the above block.

The cat statement prints a formatted version.  The str statement shows
what R sees (but the outer quotes are not part of the string).

#+BEGIN_SRC R :noweb yes :results output
some.latex <- 
<<quote-blks("lstuff")>>
cat(some.latex,"\n")
str(some.latex)
#+END_SRC

#+RESULTS:
: Here is a \backslash. And an unmatched quote: '. 
:  chr "Here is a \\backslash. And an unmatched quote: '."

HTH,

Chuck