| tclVarFun {tcltk2} | R Documentation |
These functions are intended to provide a better "duality" between the name of variables in both R and tcl, including for function calls. It is possible to define a variable with the same name in R and tcl (the content is identical, but copied and coerced in the two respective environments). It is also possible to get the value of a tcl variable from R, and to call a R function from within tcl. These functionnalities are provided in the tcltk package, but Tcl variable usually have different internal names as R equivalents.
makeTclNames(names, unique = FALSE) tclFun(f, name = deparse(substitute(f))) tclGetValue(name) tclSetValue(name, value) tclVarExists(name) tclVarFind(pattern) tclVarName(name, init = "", keep.existing = TRUE)
names |
transform names so that they are valid for variables in Tcl. |
unique |
should these names be unique in the vector? |
f |
an R function. currently, do no support functions with arguments. |
name |
the name of a variable. |
value |
The value to place in a variable. |
pattern |
a pattern to search for. |
init |
initial value to use when creating the variable. |
keep.existing |
if the tcl variable already exist, should we keep its content? |
These functions are similar to tclVar() from package tcltk, except for
the following change: here, it is possible to propose a name for the created
tcl variable, or to set or retrieve the content of a tcl variable that is not
mirrored in R.
Most of these functions return a tclVar object.
Philippe Grosjean
## Not run:
## These cannot be run by examples() but should be OK when pasted
## into an interactive R session with the tcltk package loaded
## Tcl functions and variables manipulation
tclVarExists("tcl_version")
tclVarExists("probably_non_existant")
tclVarFind("tcl*")
## Using tclVarName() and tclGetValue()...
## intented for better match between R and Tcl variables
Test <- tclVarName("Test", "this is a test!")
## Now 'Test' exist both in R and in Tcl... In R, you need to use
tclvalue(Test) # to retrieve its content
## If a variable already exists in Tcl, its content is preserved using
## keep.existing = TRUE
## Create a variable in Tcl and assign "just a test..." to it
tclSetValue("A_Variable", "just to test...")
## Create the dual variable with same name
A_Variable <- tclVarName("A_Variable", "something else?")
tclvalue(A_Variable) # Content of the variable is not changed!
## If you want to retrieve the content of a Tcl variable,
## but do not want to create a reference to it in R, use:
## Create a Tcl variable, not visible from R
tclSetValue("Another_Variable", 1:5)
tclGetValue("Another_Variable") # Get its content in R (no conversion!)
tclSetValue("Another_Variable", paste("Am I", c("happy", "sad"), "?"))
tclGetValue("Another_Variable") # Get its content in R (no conversion!)
## End(Not run)