[R] delay evaluation of expression

[Luca Cerone]

Dear all,
in one of my packages I need to load some data from .Rdata files that
are to be used from
some functions (but not all off them). I would like to delay the
loading of this datasets
only when needed. In other cases I successfully used lazyLoad and
delayedAssign(),
but when I try to load a .Rdata file I get this message: Error: cannot
add bindings to a locked environment

What would be the best way to load such a db only the first time that is needed?
Thanks a lot for you help,

Cheers,
Luca