Hello

On 26/02/2008, Andrew Dunstan <[EMAIL PROTECTED]> wrote:
>
>
>  Pavel Stehule wrote:
>  > Hello,
>  >
>  > I found easy implementation of variadic functions. It's based on
>  > adapation FuncnameGetCandidates. When I found variadic function, then
>  > I should create accurate number of last arguments (diff between
>  > pronargs and nargs). Variadic function can be signed via flag or via
>  > some pseudotype. Flag is better - allows variadic arguments of any
>  > type. In static languages (like SQL or PL/pgSQL) variadic variables
>  > can ba accessed via array (variadic arguments can be only nonarray).
>  > This isn't problem in C language, there are arguments available
>  > directly.
>  >
>
>
> There are a whole slew of questions around this, ISTM.

sure. It's time to thing about it.

>
>  For example: What will be the type inferred for the array of variadic
>  args in plpgsql?

SQL and PL/SQL should be limited.  In my prototype I use fragment:

                /* replace ANYNONARRAYS argument with ARRAY OF some */
               argtype = get_array_type(argtype);
               if (!OidIsValid(argtype))
                                    ereport(ERROR,
                                         (errcode(ERRCODE_DATATYPE_MISMATCH),
                                          errmsg("could not determine
actual array type for variadic argument")));

SPI is unlimited (C language). I can use list of arrays in perl or
python - there I don't see complications too. Domains and arrays can
be problem. Using variadic array variables isn't typical. So I will to
solve only domains. But it's more general problem. Maybe 8.4 can
support array of domains.

>
>  If we are going to do this I think we need some discussion on design
>  before we rush into it.
>

yes, I agree. Variadic functions are simple. And I belive it can
simplify life to some programmers that have to manage functions like:

foo(int),
foo(int, int)
foo(int, int, int)...

regards
Pavel



>  cheers
>
>
>  andrew
>
>
>
>

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