[R] getting caller's environment

[Yi Zhang]

Hello,

I'm writing a function like this:

f<-function(x,y,...) {
...
assign(x,y,envir=?)
}

I need the caller (of f) 's environment for the "?" so that the
assignment is done at the right place. To be specific, when the code
"f(x,1)" appears in environment A, I need the assignment of 1 to x
happen in environment A. So my question is how to get the correct
environment?

Thanks for any suggestions!