pg ANY/SOME ambiguity wrt sql standard?

I'm looking into adding sql standard aggregates EVERY/ANY/SOME.
It seems to me that there is a syntax ambiguity with ANY and SOME:

CREATE TABLE bla(b BOOL);
SELECT TRUE = ANY(b) FROM bla;

Is parsed as an array-operator and there is a semantical error because no
array is provided. Now ANY could be an aggregate function call, and it
should be fine.

However I really cannot see (my usual lack of imagination) how to handle
this from the parser.

Thus I'm afraid that I'll have to rewrite the A_Expr structure into a
FuncCall to 'any' or 'some' somewhere.

Comments? Any better idea?

--
Fabien Coelho - coelho(at)cri(dot)ensmp(dot)fr