Re: #1132: Allowing IP addresses as path-identiites - Poll result

[Frank Ellermann <nobody@xxxxxxxxxxxxxxxxx>]

Russ Allbery wrote:

> I'll make a brief plea to disallow [FWS] after "!" rather
> than before

For my wannabe-simplified path ABNF that would result in:

 path          = "Path:" SP [FWS] path-list [FWS] CRLF
 path-list     = *( path-entry [FWS] "!" ) tail-entry
 path-entry    = path-identity [ path-diag ]

 tail-entry    = 1*( alphanum / "-" / "_" / "." )    ; TBD ?!?

 path-identity = *( path-label "." ) path-label
 path-label    = alphanum [ *( alphanum / "-" / "_" ) alphanum ]
 alphanum      = ALPHA / DIGIT

 path-diag     = [ [FWS] "!POSTED" ]
                 [ "!" /                 ; match => "!!"
                   ( [FWS] "!"
                     ( IPv4address       ; see [RFC 3986]
                     / IPv6address       ; see [RFC 3986]
                     / path-identity ) ".MISMATCH" ) ]

If you prefer your "lazy IP-diagnostics" = Charles' .SEEN
please replace the ".MISMATCH" by ( ".SEEN" / ".MISMATCH" )
in this proposal.

Open questions:  what is allowed in a <tail-entry> ?

Is Charles ready to drop the "multi-id per entry" idea in
the syntax ?  If not adding it is simple:

--- see above ---
 path-entry    = path-identity [ path-diag ]
--- multi id. ---
 path-entry    = *( path-identity [FWS] "!" ) path-identity [ path-diag ]
--- --------- ---

So that's one proposal with two optional tweaks .SEEN and / or
"multi-id", and the <tail-entry> details TBD.  Bye, Frank