require is to suggests as what is to imports?

On Tue, 24 Aug 2010, Hadley Wickham wrote:

Hi all,

If a package suggests another package in its description, you can
check it at runtime with requires. ?How do you do check if a package

Well, not really as requires() can give an error, at least until 2.12.0 is
out. ?So you need to wrap it in a try/tryCatch construct.

is available without loading it, if you only want to access one
function in the package namespace.

You could use try/tryCatch on pkg::fun (which is what you need to do with
require). ?It is difficult (and would be fragile since the details of
metadata are definitely subject to change without notice) to ascertain what
a namespace will contain/export without loading it.