Managing class and their order
# result is of class character; it prints correctly result <- "Je suis donc je pense" class(result) print(result) # I add a new class but I keep character class. All is ok # The order of classes is not important because there is no print() function for class ECFOCF class(result) <- unique(append(class(result),"ECFOCF"))) class(result) print(result) result <- "Je suis donc je pense" class(result) <- unique(append("ECFOCF", class(result))) class(result) print(result) # I create a new function for class ECFOCF # This function is used in priority whatever the ordre of classes print.ECFOCF <- function(x) {cat("print.ECFOCF ", x)} result <- "Je suis donc je pense" print(result) class(result) <- unique(append(class(result),"ECFOCF"))) class(result) print(result) result <- "Je suis donc je pense" class(result) <- unique(append("ECFOCF", class(result))) class(result) print(result