Why doesn't R allow $ operator on atomic vectors?

Question

The following will throw the error \"Error in v$a : $ operator is invalid for atomic vectors\" (at least in R version 2.14.1):

v <- c(a=\'a\',b=\'b\')
v$a         


        

Answer 1

Third paragraph of the Details section of ?"$":

‘$’ is only valid for recursive objects, and is only discussed in the section below on recursive objects. Its use on non-recursive objects was deprecated in R 2.5.0 and removed in R 2.7.0.

R-2.7.0 was released in April, 2008. Four years is far from "recent", but maybe you have been a few versions behind for awhile?

Answer 2

I believe the reason is that the use of v$a vs. v[['a']] is considered less safe.

EDIT: Check out this LINK for more details.