Peter Eisentraut <peter_e@gmx.net> writes:
> This must have been an artifact from the time when part of the Postgres
> system was written in Lisp. A Lisp procedural language never actually
> existed in PostgreSQL.
[ Digs in archives... ] The pg_language entry that Vladimir refers to
was still present as late as Postgres 6.5 --- but I agree that it must
have been vestigial long before that. Certainly, at one time large
chunks of Postgres *were* written in Lisp, and I imagine that the
pg_language entry did something useful when that was true. But it was
dead code in Postgres 4.2 (1994), which is the oldest source I have;
there is no Lisp code remaining in 4.2.
It'd theoretically be possible to support Lisp in the same way as we
currently support Tcl, Perl, etc. The hard part is to find a suitable
interpreter that is designed to be dynamically linked into other
applications. Perl still hasn't got that quite right, and I imagine
it's an even more foreign idea for most Lisp systems...
regards, tom lane