Peter Dalgaard wrote:
>Paul Gilbert <[EMAIL PROTECTED]> writes: > > > >>>I.e., when x is missing in g, and g calls f(3,x), f will use its >>>default value for x. >>> >>> >>> >>> >>Yes, that is the behaviour I am looking for. That is, f should do what >>it normal would do if it were called with x missing. >> >> > >But if x has a default in g then that default should presumably be >used? > Yes. The value of x in g would get passed to f, default or otherwise. If that value is something that indicates x is missing, then it should be treated as if it is missing in f. This means f should use its default value, rather than throw an error saying x is missing. >And what if x is given a value in the evaluation frame of g >before it is used by f (which can happen, you know, even after the >evaluation of f has begun)? Now imagine a longer chain of calls. > >I think what you're asking for is essentially dynamic scoping for >missing arguments: you'd have to backtrack along the call chain to >find the first instance where x is either given a value or has a >default. This sounds messy. > > You understand this better than I do, but I don't think I am asking to do this. Currently I think f looks back too far and finds x is missing and g does not have a default value for x, so it throws an error. Why can't f find its own default value for x? ==================================================================================== La version française suit le texte anglais. ------------------------------------------------------------------------------------ This email may contain privileged and/or confidential inform...{{dropped}} ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel