Re: WIP: default values for function parameters

"Pavel Stehule" <pavel.stehule@gmail.com> writes:
> 2008/12/9 Tom Lane <tgl@sss.pgh.pa.us>:
>> If you could prove that it were *only* being used by this contrib module
>> then I might hold still for replacing it.  But you can't.  The odds are
>> good that people have custom data types using similarly-named operators.

> it means, so we must not implement any new operator?

No, it doesn't mean any such thing.  If we invented, say, "int4 => int4"
it would not break someone's use of => for their own custom datatype.
What you're proposing would be a global redefinition of the meaning of =>.

This is closer to creating a new reserved word, which as I'm sure you
know we try hard to avoid, even for keywords that the spec says we can
reserve.  The bar for making a new fully-reserved word that isn't in
the spec is *very* high.
        regards, tom lane