Re: URI spec production path-empty uses prose-val ABNF mechanism on purpose?

• From: Roy T. Fielding <fielding@gbiv.com>
• Date: Tue, 18 Nov 2008 12:12:56 -0800
• To: Dan Connolly <connolly@w3.org>
• Cc: uri <uri@w3.org>
• Message-Id: <F1179C22-A22E-4F6A-AE11-302D03A3B8BD@gbiv.com>

On Nov 17, 2008, at 10:12 PM, Dan Connolly wrote:

> I'm trying to do some automated processing of the URI spec,
> and I bumped into:
>
> path-empty    = 0<pchar>
>
> I wonder if those <> are there on purpose. I suppose
> it doesn't matter; 0 repetitions of anything is the empty string.
>
>
> I doubt this mechanism was invoked on purpose, though:

probably not, but it is more readable than

   path-empty  = 0pchar

I probably should have used

   path-empty  = 0*0(pchar)

but it really doesn't make any difference.

> prose-val      =  "<" *(%x20-3D / %x3F-7E) ">"
>                                ; bracketed string of SP and VCHAR
>                                   without angles
>                                ; prose description, to be used as
>                                   last resort
>
> http://tools.ietf.org/html/rfc2234#page-9

BTW, the current ABNF ref is RFC5234.

....Roy

Received on Tuesday, 18 November 2008 20:13:19 UTC