From murdoch.duncan at gmail.com  Sun Jul  6 16:22:17 2014
From: murdoch.duncan at gmail.com (Duncan Murdoch)
Date: Sun, 06 Jul 2014 10:22:17 -0400
Subject: [Rd] Depot for S3 to S4 generics (as in stats4)?
In-Reply-To: <CAHuTOvr+S5cZ7VrymLgp3S-pLhBkUsHoPzifDWJs0NPMdVZk+Q@mail.gmail.com>
References: <CAHuTOvr+S5cZ7VrymLgp3S-pLhBkUsHoPzifDWJs0NPMdVZk+Q@mail.gmail.com>
Message-ID: <53B95B99.9080006@gmail.com>

On 06/07/2014, 6:23 AM, Sven E. Templer wrote:
> Dear developers,
> 
> the implementation of S4 generics for existing S3 ones in the base
> package is concerned to be a threat to quick startup times [1]. But
> since S4 is promoted, and S3/S4 interoperability a pain when package
> developing [2], are there efforts to improve the situation? E.g. an S3
> free system, etc.
> 
> A good thing [2] is the package 'stats4', including some setGeneric
> calls (e.g. for summary, plot, ...) which I can 'importFrom' to a
> NAMESPACE. Nevertheless, functions as as.matrix, as. dist, merge,
> duplicated, and for sure some others, are not available as S4
> generics.
> So my question is: will the base/graphics/... S3 generic definitions
> for S4 methods be completely implemented in a future R release?
> (E.g. in base4/stats4,/graphics4/... (by heritage [3]) or combined by
> a single package such as genericS4)

I would not do that, and I haven't seen anyone else announcing plans to
do it, but the question is pretty open ended.  I'm reluctant to make
predictions about what R will look like in the indefinite future.  I
would be confident in guessing that R 3.2.x won't include it (but I
could be wrong, if someone takes it on).

If you want to make it happen sooner, you need to find an R Core member
to work with.  Presumably the responses to your posting will indicate
the level of interest in working on this.

Duncan Murdoch

> Sorry I couldn't get more information from the devel archive (or find
> a solution/answer) since the same idea already has been mentioned in
> 2007 [4]. Thank you for clarifying in advance.
> 
> Sincerely,
> Sven
> 
> [1] http://r.789695.n4.nabble.com/An-update-method-for-lists-td912749.html#a912756
> [2] my opinion
> [3] http://r.789695.n4.nabble.com/improved-error-message-when-existing-implicit-S4-generic-is-not-imported-td4421688.html#a4436278
> [4] http://developer.r-project.org/BDR_S4issues.txt
> 
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>



[Rd] Depot for S3 to S4 generics (as in stats4)?
Duncan Murdoch