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@xxxxxxxxx> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.
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