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

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
>>>
>>>_______________________________________________
>>>ddlm-group mailing list
>>><mailto:ddlm-group@iucr.org>ddlm-group@iucr.org
>>><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
>><mailto:ddlm-group@iucr.org>ddlm-group@iucr.org
>><http://scripts.iucr.org/mailman/listinfo/ddlm-group>http://scripts.iucr.org/mailman/listinfo/ddlm-group
>>
>>
>>_______________________________________________
>>ddlm-group mailing list
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>>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
>                   yaya@dowling.edu
> =====================================================
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