Re: proposal: plpgsql - Assert statement

2014-11-19 23:54 GMT+01:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Marko Tiikkaja <marko(at)joh(dot)to> writes:
> > I also went back to the original thread, and I think Heikki's summary
> > dismissed e.g. Robert's criticism quite lightly:
> >
> http://www.postgresql.org/message-id/CA+TgmobWoSSRNcV_iJK3xhsytXb7Dv0AWGvWkMEurNTOVEZYyw@mail.gmail.com
>
> The core of that complaint is that we'd have to make ASSERT a plpgsql
> reserved word, which is true enough as things stand today. However,
> why is it that plpgsql statement-introducing keywords need to be
> reserved? The only reason for that AFAICS is to allow us to distinguish
> the statements from assignments. But it seems like that could possibly
> be gotten around with some work. The first thing that comes to mind is
> for the lexer to do one-token lookahead and assume that the second
> token of an assignment must be ":=" (aka "="), ".", or "[". (Have
> I missed any cases?) Then, any statement for which the second token
> can't be one of those, which is surely most if not all of them, could
> have an unreserved leading keyword. This would at a stroke dereserve
> about half of plpgsql's existing reserved words, as well as remove a
> roadblock for ASSERT and other new statements.
>

Doesn't it close a doors to implement a procedures call without explicit
CALL statement (like PL/SQL) ?

Personally I doesn't feel to introduce lot of new keywords (statements) to
plpgsql. Probably only two - ASSERT (assertions), PRAGMA (some cooperation
with plpgsql extensions).

>
> regards, tom lane
>