# [Rd] some (minor) Rd issue: line breaking in \S4method within \usage{}

Duncan Murdoch murdoch at stats.uwo.ca
Mon Sep 7 15:23:35 CEST 2009

On 07/09/2009 7:27 AM, Peter Ruckdeschel wrote:
> Hi,
>
> this is perhaps not so much an issue, but as you are currently
> working on the Rd parser anyway...
>
> When you want to document specific S4 methods for an S4 generic
> by \S4method{} within a \usage{} environment, and the second
> (signature_list) argument is "long", be it because you use multiple
> dispatch, be it because you use long class-names, (or both), one
> would probably like to be able to insert line breaks within the
> signature list [or at least insert line breaks at suitable places
> in the corresponding generated pdf file].
>
> AFAICS this is not possible so far, at least I get errors in
> R CMD check, whenever I try something like
>
> \S4method{<myMethod>}{<ClassOf1stArgToDispatch>,
> <ClassOf2ndArgToDispatch>}(<Name1stArgToDispatch>,<Name2ndArgToDispatch>)
>
> i.e. if I insert a line break in the Rd file after any item of the
> signature_list argument to \S4method.
>
> Using line breaks in the the third (argument_list) argument is not a
> problem, though.
>
> So my little RFE would be to ask you to allow some optional line
> breaking mechanism for the second argument of \S4method, too,
> if this is not too hard to achieve.

Do you get these errors in R-devel?  (If you'd posted a real example,
I'd try it myself, but this is your wishlist item...)

Duncan Murdoch