Re: proposal: plpgsql, solution for derivated types of parameters

Pavel Stehule <pavel.stehule@gmail.com> writes:
> the current plpgsql syntax doesn't offer a functionality to define
> some variable with type as element of some other array variable or
> reverse order. The primary goal of this proposal is enahancing plpgsql
> for better working with polymorphic types.

I haven't seen any actual field complaints that would be solved by this.
How often is it really going to be useful?

> DECLARE elementvar IS ELEMENT OF arrayvar;
> DECLARE arrayvar IS ARRAY OF varname;

Both of these notations seem pretty inconsistent with the rest of
plpgsql, as well as being dead ends when you think about extensions to
more complex situations like arrays of records or records of arrays.
I'd expect to do the former with something like "arrayvar[0]%type" and
the latter with "var%type[]".  Possibly some parentheses would be needed
to make this non-ambiguous.
        regards, tom lane