Robert Haas <robertmhaas@gmail.com> writes:
> I agree that redefining the lexer behavior is a can of worms. What I
> don't understand is why f(2+2) can't call f(smallint) when that's the
> only extant f. It seems to me that we could do that without breaking
> anything that works today: if you look for candidates and don't find
> any, try again, allowing assignment casts the second time.
Yeah, possibly. Where would you fit that in the existing sequence of
tests?
http://www.postgresql.org/docs/devel/static/typeconv-func.html
regards, tom lane