[Rd] Identical copy of base function
Martin Maechler
maechler at stat.math.ethz.ch
Mon Feb 27 13:03:31 CET 2012
>>>>> Matthew Dowle <mdowle at mdowle.plus.com>
>>>>> on Mon, 27 Feb 2012 09:59:43 +0000 writes:
> Hello,
> Regarding this in R-devel/NEWS/New features :
> o 'library(pkg)' no longer warns about a conflict with a
> function from 'package:base' if the function is an
> identical copy of the base one but with a different
> environment.
> Why would one want an identical copy in a different
> environment? I'm thinking I may be missing out on a trick
> here.
Yes, you are ;-) The trick is called ``namespace'' :
One example which lead me to implement the above:
The Matrix package has had an identical copy of 'det' for a
while now, but of course in the Matrix namespace.
Because of that, the call to determinant() inside det() will
correctly dispatch Matrix methods for determinant(), whereas
base::det() would not.
Martin
More information about the R-devel
mailing list