Re: Bug #534: factorial function

Thomas Lockhart <lockhart@fourpalms.org> writes:
>> ... I'd be sorely tempted to replace all three by a single
>> function that takes integer and returns numeric.

> Yikes. Although numeric is theoretically nice, it is hundreds of times
> slower than native doubles.

(a) As a wise man once said, "I can make it arbitrarily fast, if it
doesn't have to give the right answer".  (b) The factorial function
doesn't strike me as a performance bottleneck.  (c) I have no objection
to offering a double-precision-based gamma function alongside the
integer factorial function.  But I think factorial should give an exact
answer as far as is possible before it overflows.

            regards, tom lane