R devel - Jan 2007 - Scoping issues

Hi everyone,

I'm trying to split up a large R file that implements a tcl/tk gui into
several smaller ones.  The problem is that the main GUI creation
function defines many tclVars and tkframes that need to be accessible to
functions that are currently defined in main function, but which I'd
like to move to different source files.  These files make up a package,
so it seems that using source() is a bad idea.  I could try argument
passing, but there are a lot of arguments to pass in some cases.

The lexical scoping is hurting me here, but I assume there's a good way
to deal with this kind of issue.  Any help is greatly appreciated.

-Chris

Dear Chris,

If I correctly understand what you want to do, the Rcmdr package uses the
following functions (slightly modified from original version contributed by
Philippe Grosjean) to solve a similar problem:

RcmdrEnv <- function() {
    pos <-  match("RcmdrEnv", search())
    if (is.na(pos)) { # Must create it
        RcmdrEnv <- list()
        attach(RcmdrEnv, pos = length(search()) - 1)
        rm(RcmdrEnv)
        pos <- match("RcmdrEnv", search())
        }
    return(pos.to.env(pos))
    }

putRcmdr <- function(x, value)
    assign(x, value, envir = RcmdrEnv())

getRcmdr <- function(x, mode="any")
    get(x, envir = RcmdrEnv(), mode = mode, inherits = FALSE)

I hope this helps,
 John

--------------------------------
John Fox
Department of Sociology
McMaster University
Hamilton, Ontario
Canada L8S 4M4
905-525-9140x23604
http://socserv.mcmaster.ca/jfox 
-------------------------------- 
> -----Original Message-----
> From: r-devel-bounces at r-project.org 
> [mailto:r-devel-bounces at r-project.org] On Behalf Of Chris Eisley
> Sent: Sunday, January 07, 2007 12:29 AM
> To: r-devel at r-project.org
> Subject: [Rd] Scoping issues
> 
> Hi everyone,
> 
> I'm trying to split up a large R file that implements a 
> tcl/tk gui into several smaller ones.  The problem is that 
> the main GUI creation function defines many tclVars and 
> tkframes that need to be accessible to functions that are 
> currently defined in main function, but which I'd like to 
> move to different source files.  These files make up a 
> package, so it seems that using source() is a bad idea.  I 
> could try argument passing, but there are a lot of arguments 
> to pass in some cases.
> 
> The lexical scoping is hurting me here, but I assume there's 
> a good way to deal with this kind of issue.  Any help is 
> greatly appreciated.
> 
> -Chris
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel