... and probably a dumb one and almost certainly not of interest to most R users. But anyway...
?"+" says: "The unary and binary arithmetic operators are generic functions: methods can be written for them individually or via the Ops group generic function. " So: "+.character" <- function(e1, e2) paste0(e1, e2) ## but this doesn't 'work': > "a" + "b" Error in "a" + "b" : non-numeric argument to binary operator ## but explicitly invoking the method does 'work' : > "+.character"('a','b') [1] "ab" ##Note also: > methods("+") [1] +.character +.Date +.IDate* +.POSIXt +.trellis* So what am I failing to understand? Thanks. Bert Gunter ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.