introspective capabilities

Duncan Murdoch <murdoch.duncan at gmail.com> writes:
On 27/08/2010 7:52 AM, Christophe Rhodes wrote:
Hi,

Is there any way, from R code, to perform introspection as to where
certain names acquired their values?
There's the "keep.source" option to source() and the optional
"srcfile" argument to parse() that tell R to keep this information.
If you haven't changed the default
getOption("keep.source") from TRUE, then source will default to
keeping it, and you can find the original location of a function
definition for function f by looking in attr(body(f), "srcref").  See
?srcref for the format; there aren't a lot of user-level utility
functions for working with this.
Thanks.  This is enough for my immediate purposes: supporting
single-keystroke (M-.) jumping to source locations of functions.
For packages, the relevant option is "keep.source.pkgs" at the time
the package is installed.
Thank you.

Is there anything like a cross-referencing database within R?  The
functionality I'm looking for here is to be able to name a function, and
come back with a list of functions (or srcrefs) where that name is
used.  (I realise that this is not in general possible; just the
lexically-apparent cases would be enough).

Cheers,

Christophe
Duncan Murdoch <murdoch.duncan at gmail.com> writes:

On 27/08/2010 7:52 AM, Christophe Rhodes wrote:
Hi,

Is there any way, from R code, to perform introspection as to where
certain names acquired their values?
There's the "keep.source" option to source() and the optional
"srcfile" argument to parse() that tell R to keep this information.
If you haven't changed the default
getOption("keep.source") from TRUE, then source will default to
keeping it, and you can find the original location of a function
definition for function f by looking in attr(body(f), "srcref").  See
?srcref for the format; there aren't a lot of user-level utility
functions for working with this.
Thanks.  This is enough for my immediate purposes: supporting
single-keystroke (M-.) jumping to source locations of functions.

For packages, the relevant option is "keep.source.pkgs" at the time
the package is installed.
Thank you.

Is there anything like a cross-referencing database within R?  The
functionality I'm looking for here is to be able to name a function, and
come back with a list of functions (or srcrefs) where that name is
used.  (I realise that this is not in general possible; just the
lexically-apparent cases would be enough).
There is no such database already built, but I imagine the functions in 
the codetools package could construct one. 

Duncan Murdoch
Hi Christophe

You could also look at the 'foodweb' function in package 'mvbutils'-- and specifically 'callers.of'. It should do just what you want, though you do have to tell it which environments to search through.

bye
Mark
Mark Bravington
CSIRO Mathematical & Information Sciences
Marine Laboratory
Castray Esplanade
Hobart 7001
TAS

ph (+61) 3 6232 5118
fax (+61) 3 6232 5012
mob (+61) 438 315 623

Christophe Rhodes wrote:
> Duncan Murdoch <murdoch.duncan at gmail.com> writes:
> 
>> On 27/08/2010 7:52 AM, Christophe Rhodes wrote:
>>> Hi,
>>> 
>>> Is there any way, from R code, to perform introspection as to where
>>> certain names acquired their values?
>> 
>> There's the "keep.source" option to source() and the optional
>> "srcfile" argument to parse() that tell R to keep this information.
>> If you haven't changed the default
>> getOption("keep.source") from TRUE, then source will default to
>> keeping it, and you can find the original location of a function
>> definition for function f by looking in attr(body(f), "srcref").  See
>> ?srcref for the format; there aren't a lot of user-level utility
>> functions for working with this.
> 
> Thanks.  This is enough for my immediate purposes: supporting
> single-keystroke (M-.) jumping to source locations of functions. 
> 
>> For packages, the relevant option is "keep.source.pkgs" at the time
>> the package is installed.
> 
> Thank you.
> 
> Is there anything like a cross-referencing database within R?  The
> functionality I'm looking for here is to be able to name a function,
> and come back with a list of functions (or srcrefs) where that name
> is used.  (I realise that this is not in general possible; just the
> lexically-apparent cases would be enough).    
> 
> Cheers,
> 
> Christophe
> 
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