Re: [R] R extensions

From: Duncan Murdoch <>
Date: Sat, 12 Jan 2008 14:27:56 -0500

On 12/01/2008 2:13 PM, Edna Bell wrote:
> Dear R Gurus:
> I'm reading through the "Writing R Extensions" manual.
> I am seeing references to "load hooks" and SEXPR but have no ideas
> what these are.
> Could someone give me some direction as to finding out about these, please?

SEXP is the name in the C language for the type that stores a pointer to an R object. Usually you use the macros defined in Rinternals.h and R.h (and headers they load). The definition of the internal structure is also there, but you normally don't need to make use of it.

Load hooks have their own section in the R Extensions manual. They are functions that are called at the time packages (or other things) are loaded, so they can do initialization, etc.

If you really want to look at the gory details, see the R Internals manual. You rarely need to look there, but when you need it, you can probably trust that manual to be more accurate than the others, which sometimes fall out of date in some details.

Duncan Murdoch mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Sat 12 Jan 2008 - 19:31:34 GMT

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