Re: lexing small ints as int2

Robert Haas <robertmhaas@gmail.com> writes:
> I am not too sure that the distinction between implicit casts and
> assignment casts is all that useful;

We've been there and done that; it doesn't work.  The current scheme
was invented specifically because a two-way design didn't work.

http://archives.postgresql.org/pgsql-hackers/2002-09/msg00900.php
        regards, tom lane