Hello, Section 4.3.2 of the R language definition [1] states that argument matching to formal arguments is a 3-pass process to match arguments to a function. An error is generated if any (supplied) arguments are left unmatched. Interestingly the opposite is not true as any unmatched formals does not generate an error.
> f <- function(x,y,z) x > f(2) [1] 2 > f(2,3) [1] 2 Since R is lazily evaluated, I understand that it is not an error for an unused argument to be unassigned. However, it is surprising to me that a function need not be called with all its required arguments. I guess in this situation technically "required arguments" means required and referenced arguments. > f() Error in f() : argument "x" is missing, with no default Can anyone shed light on the reasoning for this design choice? Warm Regards, Brian Rowe [1] http://cran.r-project.org/doc/manuals/r-release/R-lang.html#Argument-matching [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
