From spinuvit at gmail.com  Wed Nov 16 17:18:33 2011
From: spinuvit at gmail.com (Vitalie Spinu)
Date: Wed, 16 Nov 2011 17:18:33 +0100
Subject: [Rd] Injecting source reference from external editors (emacs).
Message-ID: <CAAQMm-8Zm6j5+BBwq9SdEDrZKJc5=yUWogEYWrA54WQcpoUHjg@mail.gmail.com>

Hi  everyone,

I would like to inject source reference into R objects from external editor.  In
my case it's  emacs with ESS and ess-tracebug
(http://code.google.com/p/ess-tracebug/).

Currently the user has to source the file before the src references become
available. I would like to spare her, and insert the source references "on-line"
during normal interaction (i.e. sending chunks of code from emacs buffers)

With new additions in R-14 I started looking into it and discovered that an
encapsulation

eval(parse(text = "tf <- function(a){a^5
  b <- a;
  return(b)
}", srcfile = srcfile("@buffer@")))

does quite a good job, and the debugger  would display something like:

Browse[2]> debug at @buffer@#2: b <- a
Browse[2]> debug at @buffer@#3: return(b)

which is great, and could be used for what I want.

The problem is that I have to interfere with the user's input, which might not
be a good idea always. Is there (will be?) a more direct way of doing
this without encapsulation?

Currently when a function "tf<-function(a){a^5}" is created at R
prompt, R associates
with it a srcref with empty srcfile reference.

I wonder if it would be possible to instruct R that next evaluation will be from
buffer "Xbuf" at line N, something like

setSrcSource(srcobject="buffX", srcline=45)

so that any input that follows, would get a srcref pointing to "buffX" starting
from line 45 instead of just empty reference?

At the end of the evaluation I would just reset R with

setSrcSource(NULL)

Thanks,
Vitalie.



[Rd] Injecting source reference from external editors (emacs).
Vitalie Spinu