Thank you both for very helpful answers. I have indeed missed the help pages about "(" and now the situation is more clear.
> You can use this syntax by defining a function `x<-` <- function(...) {} > and it could be an S3 method, but it is a completely separate object from > x. Unfortunately, it won't work as assignment function form treats the first argument specially. My intention was to create syntactic sugar like x$metadata(condition) <- newvalue instead of x$setMetadata(condition, value=newvalue) I know that metadata(x, condition) <- newvalue would work, but I would like to avoid that particular syntax for a number of reasons. Well, you can't have everything, I guess. I'll just stick to the [] operator. Thanks again for the clarification! -- View this message in context: http://r.789695.n4.nabble.com/Method-dispatch-for-function-call-operator-tp3215381p3215590.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.