[R] setting options only inside functions

[William Dunlap]

> From: h.wickham at gmail.com [mailto:h.wickham at gmail.com] On 
> Behalf Of Hadley Wickham
> Sent: Wednesday, April 27, 2011 2:21 PM
> To: luke-tierney at uiowa.edu
> Cc: William Dunlap; r-help at r-project.org
> Subject: Re: [R] setting options only inside functions
> 
> > Put together a list and we can see what might make sense.  If we did
> > take this on it would be good to think about providing a reasonable
> > mechanism for addressing the small flaw in this function as it is
> > defined here.
> 
> In devtools, I have:
> 
> #' Evaluate code in specified locale.

S+ has a Sys.withlocale() that is a bit more general than
your with_locale():
  > Sys.withlocale
  function(expr, category = "LC_ALL", locale)
  {
          cur.locale <- Sys.getlocale(category)
          on.exit(Sys.setlocale(category = category, locale = cur.locale))
          Sys.setlocale(category = category, locale = locale)
          expr
  }

> with_locale <- function(locale, expr) {
>   cur <- Sys.getlocale(category = "LC_COLLATE")
>   on.exit(Sys.setlocale(category = "LC_COLLATE", locale = cur))
> 
>   Sys.setlocale(category = "LC_COLLATE", locale = locale)
>   force(expr)
> }
> 
> (Using force here just to be clear about what's going on)
> 
> Bill discussed options().  Other ideas (mostly from skimming 
> apropos("set")):
> 
>  * graphics devices (i.e. automatic dev.off)

Also, for setting and restoring graphics parameters with par().

>  * working directory (as in the chdir argument to sys.source)
>  * environment variables (Sys.setenv/Sys.getenv)
>  * time limits (as replacement for transient = T)