[whatwg] Parsing RFC3339 constructs
ian at hixie.ch
Tue Jun 30 21:35:44 PDT 2009
On Fri, 5 Jun 2009, Julian Reschke wrote:
> Ian Hickson wrote:
> > On Fri, 5 Jun 2009, Julian Reschke wrote:
> > > Ian Hickson wrote:
> > > > > Michael(tm) Smith wrote:
> > > > > > It seems pretty clear that there isn't anything else to refer
> > > > > > to for the date/time parsing rules -- but to me at least,
> > > > > > specifying those rules seems orthogonal to specifying the
> > > > > > date/time syntax, and I would think the syntax could just be
> > > > > > defined by making reference to the productions in RFC 3339
> > > > > > (instead of completely redefining them), while stating any
> > > > > > exceptions.
> > > > > >
> > > > > >  http://tools.ietf.org/html/rfc3339#section-5.6
> > > > > >
> > > > > > I think the exceptions might just amount to:
> > > > > >
> > > > > > - the literal letters T and Z must be uppercase
> > > > > Any technical reason why they have to?
> > > > Not really. We just need a separator.
> > > So why make it different from RFC 3339?
> > Limiting the syntax to the simplest possible syntax was an intentional
> > design choice intended to ease the burden on implementors and authors.
> > In practice, pretty much every time we've made syntax
> > case-insensitive, we've ended up having trouble because of it.
> If this was a totally new syntax, I would agree.
> But as something based on ISO8601 (and thereby also RFC 3339) it appears
> to be a bad idea to make it less compatible just for that reason.
We've seriously simplified the ISO-8601 syntax in many more ways than just
this. This was a conscious design decision.
> > The HTML5 spec defines exactly how to parse dates. Implementors are
> > required to implement what the spec describes, so reusing libraries is
> > implicitly not likely to be useful here. RFC3339 isn't even a
> > particularly important one in the grand scheme of things (ISO8601
> > comes to mind as a much higher-profile example).
> I think it's unfortunate that HTML5 doesn't allow using an off-the-shelf
> parser. But if it doesn't, and the temptation *will* be there to use
> them, I'd recommend stating it very clearly.
Ian Hickson U+1047E )\._.,--....,'``. fL
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