+ ## horrendous KLUDGE: we need to short-circuit here for "name"
+ ## objects, rather than having a nice uniform behaviour, because
+ ## for expressions of the form x[y,] there is an empty "name"
+ ## which ends up becoming a `missing' object when passed through
+ ## the switch; why, I do not know, but it is then impossible to
+ ## return it, because returning it attempts to evaluate it and
+ ## evaluating it is an error. Fortunately it appears that names
+ ## don't have srcrefs attached.
+ if(mode(s) == "name") {
+ return(s)
+ }
+ if(is(s, "srcref")) {
+ ## more monumental KLUDGE: parsing (in 2.14, at least) appears
+ ## to put srcrefs directly in `length 2' objects, which we need
+ ## to frob directly.
+ return(frob(list(s))[[1]])
+ }