Re: factorial function/phase out postfix operators?

On 5/18/20 4:42 PM, Peter Eisentraut wrote:
> There have been occasional discussions about deprecating or phasing out
> postfix operators, to make various things easier in the parser.
>
> The first step would in any case be to provide alternatives for the
> existing postfix operators.  There is currently one, namely the numeric
> factorial operator "!".  A sensible alternative for that would be
> providing a function factorial(numeric) -- and that already exists but
> is not documented.  (Note that the operator is mapped to proname
> "numeric_fac".  The function "factorial" maps to the same prosrc but is
> otherwise independent of the operator.)
>
> So I suggest that we add that function to the documentation.

I think this should be done regardless.

> (Some adjacent cleanup work might also be in order.  The test cases for
> factorial are currently in int4.sql, but all the factorial functionality
> was moved to numeric a long time ago.)
>
> What are the thoughts about then marking the postfix operator deprecated
> and eventually removing it?

I am greatly in favor of removing postfix operators as soon as possible.
--
Vik Fearing