On Tue, May 16, 2006 at 10:53:10AM -0700, Don Y wrote:
> But what *binds* my C declaration to the corresponding SQL
> "CREATE CAST"?
>
> E.g.,
>
> CREATE FUNCTION foo_from_baz(baz)
> RETURNS foo
> AS '...'
> LANGUAGE 'C' IMMUTABLE STRICT;
Your create functions would look like:
CREATE FUNCTION foo(baz)
RETURNS foo
AS '$libdir/yourlib','cast_foo_from_baz'
LANGUAGE 'C' IMMUTABLE STRICT;
CREATE FUNCTION foo(baz2)
RETURNS foo
AS '$libdir/yourlib','cast_foo_from_baz2'
LANGUAGE 'C' IMMUTABLE STRICT;
> yet, to support the foo(baz) syntax, I would then need (?)
> to continue with:
>
> CREATE CAST (baz AS foo)
> WITH FUNCTION foo(baz);
Indeed, and also:
CREATE CAST (baz2 TO foo)
WITH FUNCTION foo(baz2)
Hope this helps,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.