draft-ietf-httpbis-p1-messaging-16 1.2.1 ABNF Extension: #rule – Invalid example?


I'm new to all this, so I'm sorry if I'm not following protocol (not sure if
I should open an Issue Ticket or start by mailing the group first)

I've found examples that do not add up in p1-messaging 1.2.1.  ABNF
Extension: #rule

>   For compatibility with legacy list rules, recipients SHOULD accept
>   empty list elements.  In other words, consumers would follow the list
>   productions:
>     #element => [ ( "," / element ) *( OWS "," [ OWS element ] ) ]
>     1#element => *( "," OWS ) element *( OWS "," [ OWS element ] )
>  For example, given these ABNF productions:
>     example-list      = 1#example-list-elmt
>     example-list-elmt = token ; see Section 3.2.3
>   Then these are valid values for example-list (not including the
>   double quotes, which are present for delimitation only):
>     "foo,bar"
>     " foo ,bar,"
>     "  foo , ,bar,charlie   "
>     "foo ,bar,   charlie "

token is defined as 1*tchar and tchar is one character from a set of visible
character. Since space is not a tchar, token cannot contain a space.

In the second example " foo, bar,", since token cannot contain spaces, I
cant see how a space can be the first character. Given that I've read the
ABNF correctly, the only allowable first character is "," or a tchar. The
only way a space can come before token is if it's following a comma ",". So
this would be valid: ", foo ,bar,"
The same problem exists in example 3 as well,

If we look at example 3 and example 4 they end with spaces. That's not
allowed. According to the rules they may only end on a tchar or ",".

I'm guessing the rules are correct, so the first and last spaces in example
2-4 should be removed.
     "foo ,bar,"
     "foo , ,bar,charlie"
     "foo ,bar,   charlie"

I hope I didn't get this completely wrong.

Håkan Canberger

Received on Tuesday, 25 October 2011 20:20:18 UTC