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Re: [ddlm-group] Fwd: Fwd: Searching for a compromise on eliding. .. .

Note that I am not proposing to seek detailed technical advice from
COMCIFS, rather some guidance on general policy directions.  Those
COMCIFS participants with a technical interest are already
participating in this discussion, and presentation of the detailed
proposals under discussion will only provoke another go-around, when
what we really would like to know is how much notice we should take of
other uses of identical syntax in general.

On Tue, Mar 1, 2011 at 12:56 PM, Herbert J. Bernstein
<yaya@bernstein-plus-sons.com> wrote:
> Dear Colleagues,
>
>  I certainly agree that we should seek whatever advice we can
> get.  I have some minor quibbles with James' estimates of costs
> of implementation of various lexers, but why not let
> any others who wish to comment make their own judgments
> of implementation costs, technical benefits, psychological
> costs and psychological benefits?  I suspect we will hear
> things none of us have thought about yet.
>
>  In any case, presenting P, P-prime, F, GP, F' and G
> seems a reasonable range of choices for this more general
> discussion.
>
>  Full steam ahead.  This should be interesting.
>
>  Regards,
>    Herbert
>
> =====================================================
>  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 Tue, 1 Mar 2011, James Hester wrote:
>
>> Perhaps we need to evaluate each of the proposals in terms of
>> technical cost/benefit and pyschological cost/benefit, with the latter
>> evaluation perhaps requiring input from our larger group of COMCIFS
>> advisers.  Recall that our task is simply to find a way of including
>> arbitrary strings in CIF text.  I restrict discussion to P, P prime
>> and the F/F'/G/GP proposals:
>>
>> In terms of technical cost/benefit, it is clear that proposals
>> F,F',G,GP require minimal cost in terms of documentation,
>> implementation and use, because the minimal number of escape sequences
>> is defined.
>>
>> The P, P' proposals are significantly more costly in terms of
>> documentation and implementation, because:
>> (i) there is more to document and implement.  The corresponding
>> benefit in terms of extra escape sequences is nil and perhaps
>> negative, as the most common impact of the extra escape sequences is
>> to require them to be escaped when they appear in target text
>> (ii) the lexer has to be changed - it must now count backslashes
>> before delimiters, and only if an odd number is found should it
>> consider that delimiter a possible first in a series.  Contrast this
>> to F,F',G and GP which simply need to match the delimiter sequence.
>>
>> I suspect that the above technical benefits are outweighed by the
>> political and psychological costs for Herbert and others.  Those
>> psychological costs seem to be:
>> (i) confusion with other syntax standards (C, Python etc.)
>> (ii) idiosyncratic behaviour driving would-be adopters away from CIF
>>
>> Is this a fair assessment?  Do we wish to consult with our large body
>> of COMCIFS advisers regarding the magnitude of the
>> psychological/political costs?
>>
>> On Tue, Mar 1, 2011 at 9:52 AM, SIMON WESTRIP
>> <simonwestrip@btinternet.com> wrote:
>>>
>>> Dear all
>>>
>>> To me, the sticking point seems to be:
>>>
>>> Do we escape delimiters explicitly or do we provide line folding that can
>>> also be used to escape delimiters if necessary?
>>>
>>> Perhaps if we can resolve this, we might be in a better position to
>>> decide
>>> between the various proposals?
>>>
>>> Cheers
>>>
>>> Simon
>>>
>>>
>>>
>>> ________________________________
>>> From: SIMON WESTRIP <simonwestrip@btinternet.com>
>>> To: Group finalising DDLm and associated dictionaries
>>> <ddlm-group@iucr.org>
>>> Sent: Monday, 28 February, 2011 22:23:20
>>> Subject: Re: [ddlm-group] Fwd: Fwd: Searching for a compromise on
>>> eliding. .
>>> . .
>>>
>>> True, the "G example is no more or less likely than an F example", but
>>> the need to use the escape sequences provided by G or F is far less
>>> likely
>>> than the
>>> need to use the escape sequences required by P or P'.
>>> I also think that "quoting chunks of CIF with that delimiter included" is
>>> an
>>> unlikely
>>> scenario, relative to the use of CIF to create those chunks in the first
>>> place.
>>>
>>> In general, by introducing P or P', we would be changing markedly how
>>> data
>>> are to be
>>> represented in a CIF, which forces me to re-evaluate the relationship
>>> between CIF1 and CIF2.
>>>
>>> A change of delimiter, along with F or F', would seem far less
>>> disruptive.
>>>
>>> Cheers
>>>
>>> Simon
>>>
>>>
>>>
>>> ________________________________
>>> From: Herbert J. Bernstein <yaya@bernstein-plus-sons.com>
>>> To: Group finalising DDLm and associated dictionaries
>>> <ddlm-group@iucr.org>
>>> Sent: Monday, 28 February, 2011 21:13:45
>>> Subject: Re: [ddlm-group] Fwd: Fwd: Searching for a compromise on
>>> eliding. .
>>> . .
>>>
>>> Dear Simon,
>>>
>>>   The G example is no more or less likely than an F example.  Whatever
>>> choice of delimiters we make, the primary purpose is to be able to quote
>>> chunk of CIF within such strings.  Once we start using any multi-line
>>> delimiter for this purpose, then that delimiter will need to be well-
>>> handled in quoting chunks of CIF with that delimiter included.  That
>>> is one more reason to prefer P, P-prime, F or GP to F' or G.
>>>
>>>   Regards,
>>>     Herbert
>>>
>>>
>>> At 8:26 PM +0000 2/28/11, SIMON WESTRIP wrote:
>>>>
>>>> Dear Herbert,
>>>>
>>>> Your G example is highly unlikely to be necessary in practice, which
>>>> is one reason I've started
>>>> to see the merits of alternative delimters that don't share a
>>>> character with other delimiters and that are
>>>> unlikely to form part of a CIF data value.
>>>>
>>>> Cheers
>>>>
>>>> Simon
>>>>
>>>>
>>>>
>>>> From: Herbert J. Bernstein <yaya@bernstein-plus-sons.com>
>>>> To: Group finalising DDLm and associated dictionaries
>>>> <ddlm-group@iucr.org>
>>>> Sent: Monday, 28 February, 2011 19:34:48
>>>> Subject: Re: [ddlm-group] Fwd: Fwd: Searching for a compromise on
>>>> eliding. . . .
>>>>
>>>> The prudent thing to do is to double every backslash you want taken
>>>> verbatim, whether it is at the end of a line or not.  One nice aspect
>>>> of P and P-prime is that you get in the habit of eliding the quote
>>>> marks as well, as in
>>>>
>>>> """This is an example of \"\"\"treble quoting\"\"\""""
>>>>
>>>> even though
>>>>
>>>> """This is an example of \"""treble quoting""\""""
>>>>
>>>> is sufficient.  It keeps your visual clues more local.  I would suggest
>>>> that those considering the merits of P and P-prime versus G and F',
>>>> consider
>>>> that in GP, the above would appear in F' as
>>>>
>>>> """This is an example of ""\
>>>> "treble quoting""\
>>>> "\
>>>> """
>>>>
>>>> and the similar G statement would be
>>>>
>>>> ``This is an example of `\
>>>> `G quoting`\
>>>> `\
>>>> ``
>>>>
>>>> which seems somewhat less clear than the more Pythonesque P, P-prime and
>>>> F one-liners
>>>>
>>>>
>>>>
>>>> At 12:29 PM -0600 2/28/11, Bollinger, John C wrote:
>>>>>
>>>>> On Monday, February 28, 2011 12:16 PM, I wrote:
>>>>>
>>>>>> F and GP would require backslash doubling when a literal backslash
>>>>>> appears at the end of a line, and also when a literal
>>>>>> double-backslash appears anywhere (in which case both backslashes
>>>>>> would need to be doubled, \\ -> \\\\).
>>>>>
>>>>> Correction: F and GP would require backslash doubling when a literal
>>>>> backslash appears at the end of a line.  In addition, given any
>>>>> sequence of n + 1 literal backslashes (n >= 0), the first n of them
>>>>> must be doubled, but doubling the last is optional unless it appears
>>>>> at the end of the line.
>>>>>
>>>>> John
>>>>>
>>>>> --
>>>>> John C. Bollinger, Ph.D.
>>>>> Department of Structural Biology
>>>>> St. Jude Children's Research Hospital
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Email Disclaimer:
>>>>> <http://www.stjude.org/emaildisclaimer>www.stjude.org/emaildisclaimer
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>> <http://scripts.iucr.org/mailman/listinfo/ddlm-group>http://scripts.iucr.org/mailman/listinfo/ddlm-group
>>>>
>>>>
>>>> --
>>>> =====================================================
>>>>   Herbert J. Bernstein, Professor of Computer Science
>>>>     Dowling College, Kramer Science Center, KSC 121
>>>>         Idle Hour Blvd, Oakdale, NY, 11769
>>>>
>>>>                   +1-631-244-3035
>>>>                   <mailto:yaya@dowling.edu>yaya@dowling.edu
>>>> =====================================================
>>>> _______________________________________________
>>>> ddlm-group mailing list
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>>>>
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>>>>
>>>>
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>>>
>>>
>>> --
>>> =====================================================
>>>   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
>>> =====================================================
>>> _______________________________________________
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>>> ddlm-group@iucr.org
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>>>
>>>
>>
>>
>>
>> --
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