In this e-mail, I suggest a new approach about the question marks, which
could lead to an easier BNF and a more readable syntax. I try to stick to
the previous versions of the EDTF drafts except regarding the question
This other approach would be the following, based on praxis in the english
language and other languages such as Swedish, for exxample. This e-mail
focuses on this suggestion. Let's consider the following sentence:
"Would (not?) it be easier?"
Here, the question mark without a right parenthesis on its right side
applies to everything on the left (of it). The question mark with a right
parenthesis on its right side applies to what is inside of the
parentheses. I consider this approach would be a good way to avoid
mistakes when metadata is stored because it reminds of the use of
parentheses as in several languages.
My suggestion is thus a syntax such as:
2011-05-09? (* "?" applies to the whole date *)
2011-05?-09 (* "?" applies to 2011-05 *)
2011?-05-09 (* "?" applies to 2011 *)
For short: A question mark without a right parenthesis immediately on its
right side is applicable to everything on its left side within the
expression. Easy, isn't it?
Let's consider parentheses, now!
2011-(05?)-09 (* "?" applies to 05 *)
2011-(05-09?) (* "?" applies to 05-09 *)
2011-05-(09?) (* "?" applies to 09 *)
For short: A question mark with a right parenthesis immediately on its
right side is applicable to everything within the parentheses. Easy, isn't
These may be mixed in expressions such as:
2011?-05-(09?) (* The first "?" applies to 2011 and the second one applies
to 09. In other words, only the month is "sure". *)
I consider that this would be quite straightforward and obvious to
understand. Furthermore, it would be easy to formulate in the BNF (thanks
to the placement of the parentheses) and easy to implement, too. It is not