[R] interactively getting alist of functions for a given package?

[Greg Minshall]

hi.

at the R prompt, i often hit, e.g., "data.table::<TAB>", to try to find
a routine in a give package.

however, some packages have a *lot* of functions (i'm looking at *you*,
ggplot2...), so if i know the routine name starts with, e.g., "set", i
can filter the returned list of routines by typing
"data.table::set<TAB>" to get a list of completions.

but, what if i know the name *contains*, but doesn't start with, "set"?

is there an obvious way to find this?  something like the unix-y
: ls /bin | grep -i "set"
?

cheers, Greg