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

Dear DDLm members,

It is clear that reintroducing commas as list delimiters is not
without issues.  I would therefore like to drop this proposal (for
now) in the interest of making progress.  I will therefore shortly be
presenting a version of the DDLm specification recast in terms of the
currently agreed CIF2 syntax.  Separately I will introduce a thread to
remove comma from the list of acceptable characters in a non-delimited

On Fri, Apr 8, 2011 at 12:40 AM, Herbert J. Bernstein
<yaya@bernstein-plus-sons.com> wrote:
> 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
> rest.
> 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
>                  +1-631-244-3035
>                  yaya@dowling.edu
> =====================================================
> 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
>> Email Disclaimer:  www.stjude.org/emaildisclaimer
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