Marsland, John
2003-Jun-13 10:31 UTC
Documenting classes and methods: was [Rd] Re: R-devel Digest, Vol 3, Issue 23
Might it be an idea to make "?" a special operator akin to "+" or "[", R users could then write their own help functions - may be even making "?" generic? With the proposed xml help system one could imagine quite sophisticated context sensitive help systems. Regards, John Marsland PS this has been a very useful debate for those of us enthusiastically using S4 methods.> -----Original Message----- > From: Duncan Murdoch [mailto:dmurdoch@pair.com] > Sent: 12 June 2003 18:54 > To: Kurt.Hornik@wu-wien.ac.at > Cc: r-devel@stat.math.ethz.ch; Gordon Smyth; John Chambers > Subject: Re: Documenting classes and methods: was [Rd] Re: R-devel > Digest, Vol 3, Issue 23 > > > On Mon, 9 Jun 2003 09:32:39 +0200, you wrote in message > <16100.14359.920512.374624@mithrandir.hornik.net>: > > > >Re using 'foo-methods' as an alias, I am not sure whether this is > >necessary in the long run. To find out which methods are > available, we > >can use showMethod(). We should eventually [see below] be able to do > >something like > > > > method ? f(x="character", y = "numeric") > > > >to access the documentation object for the given signature, > and there is > >no guarantee that an f-methods Rd object really documents all methods > >for the generic f in the package. So I think eventually we > should get > >rid of the default foo-methods alias, and just dump the ones > >corresponding to available methods. > > I hope that at this point we also implement > > ?f(x,y) > > at this point, to give the same result (where x and y are existing > objects of classes "character" and "numeric", respectively). > > Duncan Murdoch > > ______________________________________________ > R-devel@stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-devel >********************************************************************** This is a commercial communication from Commerzbank AG.\ \ This ... {{dropped}}
John Chambers
2003-Jun-13 15:14 UTC
Documenting classes and methods: was [Rd] Re: R-devel Digest, Vol 3, Issue 23
"Marsland, John" wrote:> > Might it be an idea to make "?" a special operator akin to "+" or "[", R > users could then write their own help functions - may be even making "?"In fact, "?" already is an infix operator ("grep '?' src/main/gram.y" to see the grammar part of it). Quite a bit of work has been done towards making more general use of "?". See help("?") for the general ideas. Class documentation is available this way: class ? numeric class ? MethodDefinition For Version 1.8, there will very likely be some extensions. These require a bit of change to the "?" function itself to allow more general expressions as arguments. With that in place the current consensus (I think) is to support expressions of the form: method ? f("numeric", "numeric") to access method documentation for "f" corresponding to signature c("numeric", "numeric"); and also of the form ?f(e1, e2) for method documentation for the method selected corresponding to expressions e1 and e2.> generic? With the proposed xml help system one could imagine quite > sophisticated context sensitive help systems.Indeed. There's been some nice work done. One important question may be finding the right balance between taking advantage of the nicer model provided by XML and being compatible with current R documentation. John> > Regards, > > John Marsland > > PS this has been a very useful debate for those of us enthusiastically using > S4 methods. > > > -----Original Message----- > > From: Duncan Murdoch [mailto:dmurdoch@pair.com] > > Sent: 12 June 2003 18:54 > > To: Kurt.Hornik@wu-wien.ac.at > > Cc: r-devel@stat.math.ethz.ch; Gordon Smyth; John Chambers > > Subject: Re: Documenting classes and methods: was [Rd] Re: R-devel > > Digest, Vol 3, Issue 23 > > > > > > On Mon, 9 Jun 2003 09:32:39 +0200, you wrote in message > > <16100.14359.920512.374624@mithrandir.hornik.net>: > > > > > > >Re using 'foo-methods' as an alias, I am not sure whether this is > > >necessary in the long run. To find out which methods are > > available, we > > >can use showMethod(). We should eventually [see below] be able to do > > >something like > > > > > > method ? f(x="character", y = "numeric") > > > > > >to access the documentation object for the given signature, > > and there is > > >no guarantee that an f-methods Rd object really documents all methods > > >for the generic f in the package. So I think eventually we > > should get > > >rid of the default foo-methods alias, and just dump the ones > > >corresponding to available methods. > > > > I hope that at this point we also implement > > > > ?f(x,y) > > > > at this point, to give the same result (where x and y are existing > > objects of classes "character" and "numeric", respectively). > > > > Duncan Murdoch > > > > ______________________________________________ > > R-devel@stat.math.ethz.ch mailing list > > https://www.stat.math.ethz.ch/mailman/listinfo/r-devel > > > > ********************************************************************** > This is a commercial communication from Commerzbank AG.\ \ This ... {{dropped}} > > ______________________________________________ > R-devel@stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-devel-- John M. Chambers jmc@bell-labs.com Bell Labs, Lucent Technologies office: (908)582-2681 700 Mountain Avenue, Room 2C-282 fax: (908)582-3340 Murray Hill, NJ 07974 web: http://www.cs.bell-labs.com/~jmc