Add support for psql variables about pglast HOT 2 CLOSED

Unfortunately I think that's a psql extension: the standard parameter placeholder is $n with n being a positive integer... but even that works only for some statements:

$ echo 'DELETE FROM extensions WHERE values[0] = $1' | pgpp
DELETE FROM extensions
WHERE (values)[0] = $1

There's little I can do, without support in the underlying libpg_query parser, sorry.

from pglast.

It's a shame, but thanks for the answer.

from pglast.