In meinem ständigen Bemühen, Klammern für einfache Befehle zu vermeiden, habe ich den folgenden Operator geschrieben, um ein neues Grafikfenster zu erstellen. Meine Frage ist: Besteht die Gefahr, dass ich irgendetwas in R "kaputt mache", abgesehen von der offensichtlichen Unfähigkeit, die Funktion "not" für meine Variable "newdev" auszuführen?
# function to overload "!" for one purpose only
#this is adapted from the sos package code for "???", credited to Duncan Murdoch.
# Example of how to create a specialized unary operator that doesn't require
# parentheses for its argument. So far as I can tell,
#the only way to do this is to overload an existing function or
# operator which doesn't require parentheses. "?" and "!" meet this requirement.
`!` <- function (e1, e2) {
call <- match.call()
# match.call breaks out each callable function in argument list (which was "??foo" for the sos package "???",
# which allows topicExpr1 to become a list variable w/ callable function "!" (or "?" in sos)
original <- function() {
call[[1]]<-quote(base::`!`)
return(eval(call, parent.frame(2)))
}
# this does preclude my ever having an actual
# variable called "newdev" (or at least trying to create the actual NOT of it)
if(call[[2]] =='newdev') {
windows(4.5,4.5,restoreConsole=T)
}else{
return(original()) # do what "!" is supposed to do
}
}