method_missing in R?

badhack.r

method.name <- "test"
eval(parse(text=sprintf('setGeneric("%s", function(object) standardGeneric("%s"))', method.name, method.name)))

gistfile1.r

setClass("cc", representation(x="numeric"))
setGeneric("pp", function(o) standardGeneric("pp"))
setMethod("pp", c("cc"), function(o) o@x)

setGeneric("qq", function(o) {
	f <- deparse(match.call()[[1]])
	if (!existsMethod(f, class(o)))
		print("orz")
	else
     	standardGeneric("qq")
	})

c1 <- new("cc", x=1.5)
pp(c1)
qq(c1)

method_missing.R

setClass("cc", representation(x="numeric"))
setGeneric("pp", function(o) standardGeneric("pp"))
setMethod("pp", c("cc"), function(o) o@x)

# hook missing method
method_missing <- function(cal) {
    cal <- as.list(cal)
    do.call("pp", cal[-1])
}

setGeneric("qq", function(o) {
	f <- deparse(match.call()[[1]])
	if (!existsMethod(f, class(o)))
		method_missing(match.call())
	else
     	standardGeneric("qq")
	})

c1 <- new("cc", x=1.5)
pp(c1)
qq(c1)

環境をケアしないといけないのが面倒だけど。