[R] A %nin% operator?

[Ken Williams]

Sometimes I write code like this:

> qf.a <- subset(qf, pubid %in% c(104, 106, 107, 108))
> qf.b <- subset(qf, !pubid %in% c(104, 106, 107, 108))

and I get a little worried that maybe I've remembered the precedence rules
wrong, so I change it to

> qf.a <- subset(qf, pubid %in% c(104, 106, 107, 108))
> qf.b <- subset(qf, !(pubid %in% c(104, 106, 107, 108)))

and pretty soon my code looks like fingernail clippings (or Lisp) and I'm
thinking about precedence rather than my original task.  So I write a %nin%
operator which I define as:

> `%nin%` <- function (x, table) match(x, table, nomatch = 0L) == 0L

and then I'm happy again.

I wonder, would something like this find a home in core R?  Or is that too
much syntactic sugar for your taste?

-- 
Ken Williams
Sr. Research Scientist
Thomson Reuters
Phone: 651-848-7712
ken.williams at thomsonreuters.com