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Subject: Re: [office] ISO 14977 EBNF grammar
I have to say that I am with David on this one. The lack of a range operator and the wide use of W3C EBNF make it very justifiable that we use that standard instead. wt On Wed, Apr 30, 2008 at 5:47 PM, David A. Wheeler <dwheeler@dwheeler.com> wrote: > > My point is that you can use ISO 14977 to define a range operator and > > the Unicode characters that you want to use with it. > > Sure. > > But then you're not using the standard as it is; you're using a nonstandard extension. > Better to use a standard notation that _has_ a range operator. > > > > See: http://www.open-std.org/jtc1/sc22/wg11/docs/n506.pdf, for example. > > (It uses ISO 14977 to define a range operator.) > > No it doesn't. I looked at that spec. > > Section 5.1 describes the EBNF; it has NO range operator in the EBNF > metalanguage. Which is expected, because it's using ISO's EBNF. > It also doesn't use ranges where it'd be obvious to do so, e.g., > note that 7.1 (which uses the EBNF metalanguage) has to list each character, > instead of using a range, because the EBNF has no range operator. > > Now it's true that 8.2.1 talks about a "range" operator, but this is > NOT a range operator in the EBNF notation. > That section is using EBNF to define a range operator in the language > the spec is defining. That does NOT give a "range" operator > to the EBNF itself; the ENBF continues to lack a range operator. > > Yes, this could be worked around by using prose definitions, set unions > and differences, and defining many more nonterminals. > But I see no need to use those hacks. > ISO has accepted other standards that use the W3C/XML BNF notation, and > I think we have a good technical reason for using W3C/XML BNF: lack of ranges. > The much shorter/simpler resulting spec is in my mind a good justification too. > Clearly W3C/XML is itself defined in a standard, one which is available for > all to use and was developed by a wide consensus. Heck, I suspect ISO > has ratified it (if so, you'd think it'd count as an ISO standard too). > > {Heck, ISO is willing to ratify a specification that is explicitly incompatible with > the Gregorian/ISO 8601 calendar, so using ISO standards even when they > clearly DO apply is obviously not THAT important ;-) ;-) ;-). } > > > > --- David A. Wheeler > > --------------------------------------------------------------------- > To unsubscribe from this mail list, you must leave the OASIS TC that > generates this mail. You may a link to this group and all your TCs in OASIS > at: > https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php > >
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