[Texmacs-dev] How to create a convertor like texmacs->verbatim

[Michael Lachmann]

I am trying to make it easier to work with R in TeXmacs. What often happens is 
that in an interactive session I type
in many commands one after the other - each in its own input. at some point 
everything works, and I'd like to just copy them all into a script, or maybe 
into one multiline input.

So, I'd like to be able to select text, and copy just the R part. That would be 
parts between 
<|input>
and
</input>

Since I don't know scheme well, or maybe not at all, I thought to pipe 
selection through an external program.

To do that, I first duplicated the end of 
progs/convert/rewrite/init-rewrite.scm into my init-r.scm (the part that deals 
with converting to verbatim), and modified verbatim to read verbatimR. I did 
manage to have that pipe though an external program. But I am encountering a 
strange problem:
When I select regular text, and do edit->copy to->verbatimR

all works well, the text I select is piped to the external program.

However, if I select several input/output fields from an R session, then I seem 
to get nothing. Even for a simple expression with a formula in it, nothing is 
copied.

Below is the code - this just duplicates the functionality of "verbatim", with 
a new name "verbatimR". (i.e. no piping to external program, yet)

This code works for simple text, but not for complicated text, and I don't 
understand why...

-------
(tm-define (texmacs->verbatimR x . opts)
  (if (list-1? opts) (set! opts (car opts)))
  (let* ((wrap? (== (assoc-ref opts "texmacs->verbatimR:wrap") "on"))
         (enc (or (assoc-ref opts "texmacs->verbatimR:encoding") "iso-8859-1")))
    (cpp-texmacs->verbatim x wrap? enc)))

(tm-define (verbatimR->texmacs x . opts)
  (if (list-1? opts) (set! opts (car opts)))
  (let* ((wrap? (== (assoc-ref opts "verbatimR->texmacs:wrap") "on"))
         (enc (or (assoc-ref opts "verbatimR->texmacs:encoding") "iso-8859-1")))
    (cpp-verbatim->texmacs x wrap? enc)))

(tm-define (verbatimR-snippet->texmacs x . opts)
  (if (list-1? opts) (set! opts (car opts)))
  (let* ((wrap? (== (assoc-ref opts "verbatimR->texmacs:wrap") "on"))
         (enc (or (assoc-ref opts "verbatimR->texmacs:encoding") "iso-8859-1")))
    (cpp-verbatim-snippet->texmacs x wrap? enc)))


(define-format verbatimR
  (:name "VerbatimR")
  (:suffix "txtR"))

(converter verbatimR-document texmacs-tree
  (:function-with-options verbatimR->texmacs)
  (:option "verbatimR->texmacs:wrap" "off")
  (:option "verbatimR->texmacs:encoding" "utf-8"))

(converter verbatimR-snippet texmacs-tree
  (:function-with-options verbatimR-snippet->texmacs)
  (:option "verbatimR->texmacs:wrap" "off")
  (:option "verbatimR->texmacs:encoding" "utf-8"))

(converter texmacs-tree verbatimR-document
  (:function-with-options texmacs->verbatimR)
  (:option "texmacs->verbatimR:wrap" "off")
  (:option "texmacs->verbatimR:encoding" "utf-8"))

(converter texmacs-tree verbatimR-snippet
  (:function-with-options texmacs->verbatimR)
  (:option "texmacs->verbatimR:wrap" "off")
  (:option "texmacs->verbatimR:encoding" "utf-8"))
------------


Does anyone have an idea what the problem is?

Thanks,
Michael