[Rd] accessing tcl variables within R and tcl

[Gabor Grothendieck]

On Thu, Aug 12, 2010 at 2:14 PM, Adrian Waddell <ml_a at waddell.ch> wrote:
> Dear R users,
>
> I have some troubles with dealing with tclObj objects. I try to explain
> it with a toy example:
>
> Say I define the following tcl procedure which just prints out each list
> element
>
> library(tcltk)
> .Tcl('proc test {myList} {
>    foreach i $myList {
>      puts stdout  $i
>    }
> }')
>
> and I call it with:
>
>> tcl('test',letters[1:5])    # Works as expected
>
> Now say I define a tcl variable first:
>
>> a <- tclVar("")
>> tclObj(a) <- as.tclObj(letters[1:5])
>
>> tcl('set',a)  # output list
>
> However
>
>> tcl('test',a) # does not work as expected, returns the variable name
>
> Why not? In fact, how do get the name of the "a" list in tcl (something
> like RTcl...) so I could use it as follows
>> .Tcl('test $RTcl1') #works
>
> Loops are much quicker in tcl than in R, hence I try to do some
> computations in tcl and not via wrapper function in R. I therefore need
> a way to easily access tcl variables from within R and tcl.
>

Try this:

tcl("test", tclvalue(a))