Re: Last call for comments: fmgr rewrite [LONG]

I just got my hands on the real SQL99 stuff, dated September 1999, and it
contains a function creation syntax that is strikingly similar to ours,
which would make it a shame not to at least try to play along. Below is a
heavily reduced BNF which should give you some idea -- note in particular
the NULL call conventions. Download your copy at
<ftp://jerry.ece.umassd.edu/isowg3/x3h2/Standards/>.

<schema function> ::=
CREATE FUNCTION <schema qualified name>
<SQL parameter declaration list>
RETURNS <data type>
[ <routine characteristics>... ]
[ <dispatch clause> ]
<routine body>

<dispatch clause> ::= STATIC DISPATCH /* no idea */

<SQL parameter declaration list> ::=
<left paren>
[ <SQL parameter declaration> [ { <comma> <SQL parameter declaration> }... ] ]
<right paren>

<SQL parameter declaration> ::=
[ <parameter mode> ] [ <SQL parameter name> ]
<parameter type>
[ RESULT ]

<parameter mode> ::= IN | OUT | INOUT
/* default is IN */

<routine body> ::=
<SQL routine body>
| <external body reference>

<SQL routine body> ::= <SQL procedure statement>
/* which means a particular subset of SQL statements */

<external body reference> ::=
EXTERNAL [ NAME <external routine name> ]
[ <parameter style clause> ]
[ <external security clause> ]

<routine characteristic> ::=
LANGUAGE { ADA | C | COBOL | FORTRAN | MUMPS | PASCAL | PLI | SQL }
| PARAMETER STYLE { SQL | GENERAL }
| SPECIFIC <specific name> /* apparently to disambiguate overloaded functions */
| { DETERMINISTIC | NOT DETERMINISTIC }
| { NO SQL | CONTAINS SQL | READS SQL DATA | MODIFIES SQL DATA }
| { RETURNS NULL ON NULL INPUT | CALLED ON NULL INPUT }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| <transform group specification>
| <dynamic result sets characteristic>

--
Peter Eisentraut Sernanders väg 10:115
peter_e(at)gmx(dot)net 75262 Uppsala
http://yi.org/peter-e/ Sweden