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Re: [ddlm-group] Revisiting list delimiters. .

Having already done the code for essentially those
productions in the current release of CBFlib, for me,
it is less work to adapt to James' productions for CIF2
than to disable the use of commas, so for me accepting
Nick's lists as valid is easier that making them into
a syntax error.

CIF has a long tradition of liberal parsers for reads of
CIFs, accepting a wide variety of alternate presentations
of the same information, and writers that produce nice
neat, human readable versions.  I think James' proposal
is completely consistent with that tradition.

Rather than a long repeat of the earlier discussion.  I
would suggest simply voting on James' productions independent
of the more difficult issue of any additional semantic
restrictions (e.g. what should be rejected on read as an error
even though it conforms to the productions, or what
should be accepted on read, but not written by a conformant
writer).  If the productions are acceptable, then it is
worth having the more detailed discussion.  If the productions
are not acceptable, there is no point in discussing the

As you can tell, I am in favor of James' productions.

  Herbert J. Bernstein, Professor of Computer Science
    Dowling College, Kramer Science Center, KSC 121
         Idle Hour Blvd, Oakdale, NY, 11769


On Thu, 7 Apr 2011, Bollinger, John C wrote:

> On Thursday, April 07, 2011 2:34 AM, James Hester wrote:
>> I apologise for the lack of detail in my introductory posting. If
>> there is to be no quick agreement on the following, more formal,
>> proposal, then I am happy to withdraw the proposal completely and we
>> will continue on our previously agreed path.
>> Note that I see no value in picking over Nick et. al's code as that
>> code is not the final arbiter of every detail of what is or isn't in
>> the standard - I was simply pointing out that it would be less work to
>> fix the code to conform to the new standard if we don't deviate too
>> far from the original.
>> Here is my formal proposal: that a list be described by the following
>> productions:
>> <list> = '[' <whitespace>* {<listdatavalue> {<comma or
>> whitespace><listdatavalue>}*}* ']'
>> <listdatavalue> = {<list>|<string>}<whitespace>*
> I still maintain that the situation is essentially unchanged from the 
> last time this matter was discussed.  In particular, unless I greatly 
> underestimate the relative difficulties of the software modifications 
> that would be needed, the significance of any one-time cost difference 
> for those changes is miniscule relative to that of the ongoing (but less 
> tangible) costs of adopting an otherwise inferior solution.
> I acknowledge that commas, whitespace, and combinations of those as 
> token separators all have merits, but from the perspective of CIF 
> overall, I firmly believe that whitespace as the only list token 
> separators remains the best solution.  I withhold further technical 
> commentary at this time, in the hope that it will be unnecessary.
> Regards,
> John
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