Re: [Rd] Internal flag for S4 objects

From: Uwe Ligges <>
Date: Sun 03 Sep 2006 - 16:35:07 GMT

John Chambers wrote:
> A recent revision (svn version 39077) has introduced an internal flag (a
> bit in the C structure) that is turned on by the code that generates
> objects from an S4 class.
> There are corresponding tests for an S4 object, isS4() in R and
> IS_S4_OBJECT() in C. These are fast and reliable, and should replace
> any heuristic tests previously used.
> The tests are not currently used widely, but in the future could be
> combined with some of the other recent changes to improve reliability
> and efficiency of computations with S4 objects. Most such changes are
> more likely for 2.5.x than 2.4.0.
> S4 objects in saved sessions and other binary files will not have the
> bit set, so they should be regenerated. A likely symptom that you have
> not done so is that the objects will not print automatically with the
> standard S4 method, because the internal code now checks for an S4
> object before dispatching show().
> John

Dear R-devel testers under Windows,

this means that I won't upload the newly built Windows binary packages right now, but I will rebuild all of them again under current R-devel tomorrow. They won't appear on CRAN master before Wednesday. In the meantime, the link to R-2.3.x packages will remain active and some packages simply won't work.

Uwe Ligges mailing list Received on Mon Sep 04 02:38:42 2006

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