On 29/08/2011 8:20 AM, Hadley Wickham wrote:
>>  So doesn't that break packages that use S3 but don't have a NAMESPACE?
>
>  Maybe, but since the methods are exported as functions they are also found
>  for method dispatch and imported, if another package imports from the
>  Namspace. The problem I see is what happens if method dispatch is done on a
>  package that is not attached but just the Namespace is only loaded.
>
>  Anyway, we should really recommend that package authors write NAMESPACE
>  files in case their packages are not trivial.
>  Note that there are many CRAN packages that fail under R-devel, some of them
>  sue to NAMESPACE issues.

I'm not sure I understand the approach of providing a default
NAMESPACE.  Why not just make it a requirement to pass R CMD check?
That seems like it would be a safer approach, although it would create
some work for people who have not yet started using namespaces.

About 1000 packages on CRAN didn't have a NAMESPACE file. Most of them were very simple so our default NAMESPACE is sufficient. Some of them were not so simple, and those ones really need to have a NAMESPACE.

Adding the namespace makes all of the packages more predictable and reliable (because it gives a defined search order for functions), but there's no point forcing 1000 package authors to do it if it can be done automatically. However, there are at least a few dozen who should have done it long ago, and those ones will need to do it to pass checks.

Duncan Murdoch

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