[Rd] R CMD check: is it error to setMethod for class not currently defined?

[Gordon Smyth]

At 04:37 PM 9/06/2003, you wrote:
> >>>>> Gordon Smyth writes:
>
> > Should R CMD check consider it an error to define a new method using
> > setMethod for a class which is not currently defined? It seems to me
> > that it would be best not to consider this an error.
>
>[R CMD check by itself definitely does not test for this.]
>
> > What currently happens in that setMethod issues a warning, quite
> > correctly.  This warning produces an object 'last.warning'. Then R CMD
> > check issues a WARNING that 'last.warning' is an undocumented code
> > object.
>
> > Would it be a good idea to make R CMD check disregard the object
> > 'last.warning' when checking for undocumented code objects? If people
> > agree, I could try to make a patch for the R CMD check code.
>
>Why should it?  Packages could have an object called last.warning in
>their environment---the last.warning created by warning() seems to end
>up in .GlobalEnv ...
>
>What seems to happen is that you have a package installed as a save
>image which at save time creates a warning and hence last.warning in
>.GlobalEnv.  The way installing as a save image works everything in
>.GlobalEnv gets included in the package environment.  If for some reason
>this produces something 'unwanted', it can still be removed e.g. from
>inside the package load hook(s) (e.g., your .First.lib()).  The QC
>tools, when working on installed packages, simply load and attach them,
>and perform computations on what is available then.

Thanks for this. Including the code 'rm(last.warning)' in the right place 
solves the problem.

Gordon

>Best
>-k