A function that allows the arguments in function calls to be self-referential.

R.R

#' Allow self-referential arguments in functions.
#' 
#' @param call A function call.
#' @param quote Logical; if \code{TRUE}, the supplied \code{call} is interpreted
#' as a quote, so \code{substitute} is applied.
#' @return The evaluated function call with the self-refering arguments 
#' evaluated.
#' @examples 
#'     R(plot(y = 1:10, x = y^2))
#'     R(plot(x = y^2, y = 1:10))
#'     R(plot(x = 1:10, y = x^2, xlab = x, ylab = y, main = xlab)) 
#'     
#'     simulated = R(data.frame(y  = 2*x1 + 3*x2 + rnorm(100),
#'                              x1 = rnorm(100),
#'                              x2 = rnorm(100)))

R = function(call, quote = TRUE) {
  call = if(quote) substitute(call) else call
  args = as.list(call)[-1]
  e    = new.env()
  
  for(arg in names(args)) do.call(delayedAssign, list(arg, args[[arg]], e, e))
  
  do.call(deparse(call[[1]]), as.list(e))
}

A problem with the function is that it evaluates each argument as part of "as.list(promise)". This is "do.call"-like behaviour, which goes counter to expectations in some problems. For instance, R(plot(x = y^2, y = 1:10)) whill show c(1, 4, 9 ...) on the x-axis instead of the quote y^2. Usually this isn't a big problem, but I'd like better behaviour than that.