plpgsql: support identif%TYPE[], (from ToDo)

[Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>]

Hello

I would to solve some points from ToDo. I began with TYPE [] support.
I thing, so this should be relative simple, but there are one issue.

There are syntax for declare array from scalar type -

create or replace function x(a int)
returns ... as $$
declare f a%type[] <--
begin ...

but there are not syntax for inversion - scalar from array.
Theoretically we could to define variable with same type (array) and
everywhere work with first element. Or we should to define some
syntax:

My first idea is using word element:

create or replace function x(a int[])
...
declare f a%element;
begin
...

any ideas?

regards
Pavel