[R] Packaging platform-specific functions

[Jeffrey J. Hallman]

Never mind. I RFTM'ed more carefully and found that the 'R' directory
can also have a 'unix' or 'windows' subdirectory.

jhallman at frb.gov wrote:

  jh> I have a few functions, such as screenWidth() and screenHeight(), which
  jh> I have been able to implement for a Unix/Linux environment, but not for
  jh> Windows. (Does anyone know how to find the screen dimensions in
  jh> Windows?) 

  jh> The Writing R Extensions manual tells me how to include
  jh> platform-specific sections in documentation, and even how to have
  jh> platform-specific help files.  But it doesn't say anything about when or
  jh> how to handle platform-specific code.  In particular, how do package
  jh> writers handle functions that make sense for one platform but not for
  jh> another?  I'd like to keep a single set of source code files and
  jh> generate the Windows and Linux packages from it.

  jh> Any suggestions?