[BEEPwg] BEEP header & ABNF Question

Bruce_Kahn@notesdev.ibm.com Bruce_Kahn@notesdev.ibm.com
Mon, 25 Feb 2002 15:18:09 -0500


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[Crossposting this to BEEP and CalSched WGs to insure proper coverage]

In my attempt to be come more BEEP savy and dealing with the CAP issues I 
was rereading the BEEP RFC and I think there is a small disjoin between 
the text and the ABNF that folks should be aware of (or they can point out 
where the corrective text is).  The text in Section 2.2.1.1 Frame Header says:

   The frame header consists of a three-character keyword (one of:
   "MSG", "RPY", "ERR", "ANS", or "NUL"), followed by zero or more
   parameters.  A single space character (decimal code 32, " ")
   separates each component.

(my emphasis) but the ABNF in Section 2.2.1 Frame Syntax defines each of the parameters as mandatory:

   data       = header payload trailer

   header     = msg / rpy / err / ans / nul

   msg        = "MSG" SP common          CR LF
   rpy        = "RPY" SP common          CR LF
   ans        = "ANS" SP common SP ansno CR LF
   err        = "ERR" SP common          CR LF
   nul        = "NUL" SP common          CR LF

   common     = channel SP msgno SP more SP seqno SP size

So is it just poor text in Section 2.2.1.1 or is there a case where the 
parameters are really optional? 

I ask because it makes the ABNF different if any parameter is truely 
optional and it makes the parser need a few more checks for 'skipped' 
parameters (assuming one could 'leave off', say' more as the text 
seemingly implys).

Bruce
===========================================================================
Bruce Kahn                                INet: 
Bruce_Kahn@notesdev.ibm.com
Messaging & Collaboration                 Phone: 978.399.6496
IBM Software Group                         FAX: and nothing but the FAX...
Standard disclaimers apply, even where prohibited by law...
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<br><font size=2 face="sans-serif">[Crossposting this to BEEP and CalSched WGs to insure proper coverage]</font>
<br>
<br><font size=2 face="sans-serif">In my attempt to be come more BEEP savy and dealing with the CAP issues I was rereading the BEEP RFC and I think there is a small disjoin between the text and the ABNF that folks should be aware of (or they can point out where the corrective text is). &nbsp;The text in Section 2.2.1.1 Frame Header says:</font>
<br>
<br><font size=2><tt>&nbsp; &nbsp;The frame header consists of a three-character keyword (one of:<br>
 &nbsp; &quot;MSG&quot;, &quot;RPY&quot;, &quot;ERR&quot;, &quot;ANS&quot;, or &quot;NUL&quot;), <b>followed by zero or more<br>
 &nbsp; parameters</b>. &nbsp;A single space character (decimal code 32, &quot; &quot;)<br>
 &nbsp; separates each component.</tt></font>
<br>
<br><font size=2 face="sans-serif">(my emphasis) but the ABNF in Section 2.2.1 Frame Syntax defines each of the parameters as mandatory:</font>
<br>
<br><font size=2><tt>&nbsp; &nbsp;data &nbsp; &nbsp; &nbsp; = header payload trailer<br>
<br>
 &nbsp; header &nbsp; &nbsp; = msg / rpy / err / ans / nul<br>
</tt></font>
<br><font size=2><tt>&nbsp; &nbsp;msg &nbsp; &nbsp; &nbsp; &nbsp;= &quot;MSG&quot; SP common &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;CR LF<br>
 &nbsp; rpy &nbsp; &nbsp; &nbsp; &nbsp;= &quot;RPY&quot; SP common &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;CR LF<br>
 &nbsp; ans &nbsp; &nbsp; &nbsp; &nbsp;= &quot;ANS&quot; SP common SP ansno CR LF<br>
 &nbsp; err &nbsp; &nbsp; &nbsp; &nbsp;= &quot;ERR&quot; SP common &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;CR LF<br>
 &nbsp; nul &nbsp; &nbsp; &nbsp; &nbsp;= &quot;NUL&quot; SP common &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;CR LF<br>
</tt></font>
<br><font size=2><tt>&nbsp; &nbsp;common &nbsp; &nbsp; = channel SP msgno SP more SP seqno SP size</tt></font>
<br>
<br><font size=2 face="sans-serif">So is it just poor text in Section 2.2.1.1 or is there a case where the parameters are really optional? &nbsp;</font>
<br>
<br><font size=2 face="sans-serif">I ask because it makes the ABNF different if any parameter is truely optional and it makes the parser need a few more checks for 'skipped' parameters (assuming one could 'leave off', say' more as the text seemingly implys).</font>
<br>
<br><font size=2 face="sans-serif">Bruce</font>
<br><font size=2 face="sans-serif">===========================================================================<br>
Bruce Kahn &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;INet: Bruce_Kahn@notesdev.ibm.com<br>
Messaging &amp; Collaboration &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Phone: 978.399.6496<br>
IBM Software Group &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; FAX: and nothing but the FAX...<br>
Standard disclaimers apply, even where prohibited by law...</font>
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