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Re: [ddlm-group] Relationship of CIF2 to legacy platforms

IMHO, even though Fortran is not dead yet, it's quirky I/O semantics 
should not be an important consideration for CIF2. I still write Fortran 
code, so I am not suggesting that Fortran code be neglected. However, 
still using Fortran should have a modern compiler that supports STREAM 
I/O (including GFortran), which avoids these text I/O problems.

If you have old software that you don't want to maintain, there can 
always be a CIF2-to-CIF1 utility, so that the old program will still 
work as-is. For new code, it really only makes sense to use Fortran for 
number crunching, and just use a C library to do CIF I/O.

Joe Krahn


James Hester wrote:
> By 'systems' I had in mind computer operating systems and programming
> environments, in particular multilingual support and Fortran.  So, for
> example, as Herbert's replies have been indicating, Fortran behaviour
> continues to influence the CIF standard.
> 
> On Thu, Oct 29, 2009 at 1:04 AM, David Brown <idbrown@mcmaster.ca> wrote:
>> James asks whether we should require CIF2 to support legacy systems.  I am
>> not sure what James means by 'systems'.  Are these datafiles or programs?
>> That is to say is the queston 'should CIF2 applications be able to read
>> legacy CIFs?', or 'should legacy CIF1 programs be able to read CIF2
>> datafiles?'?
>>
>> The answer to the first question is definitely 'yes'.  It is part of the
>> mandate of CIF2 that its programs should be able to process the existing
>> archive so that the archive can take advantage of the enhanced functions of
>> DDLm.  The CIF2 dictionaries will alias all the datanames appearing in the
>> CIF1 dictionaries in a way that makes such reading easy.
>>
>> The answer to the second question is almost certainly no, at least in cases
>> where the CIF data file makes use of the added syntax features.  All the
>> datanames in CIF1.0 dictionaries differ from those in the CIF2 dictionary by
>> not using a period at the end of the category part of the name and in some
>> cases the names differ in other ways.  There would be no point in trying to
>> produce CIF2 compatible CIF1 dictionaries, since the CIF1 dictionaries are
>> poorly designed for maintenance and have poor aliasing features.
>>
>> David
>>
>>
>> James Hester wrote:
>>
>> Dear All,
>>
>> I think it would be helpful to make a policy decision regarding our
>> treatment of legacy systems in CIF2.0.  This concerns first and
>> foremost Fortran derived line-length constraints, but may impact on
>> the encoding discussion in deciding which encodings might get some
>> special treatment.  There may be other such issues as well.
>> We have a few choices:
>>
>> 1. Disregard legacy system issues when designing CIF2, on the basis
>> that such systems can continue to use CIF1 and will eventually
>> disappear at about the same time that it does (sort of like ASCII and
>> Fortran...)
>>
>> 2. Continue to support legacy systems on the basis that we don't want
>> to deny such systems the chance to partake of the raw unadulterated
>> goodness of CIF2, or perhaps more seriously that such legacy systems
>> are integral to CIF2 takeup.
>>
>> What do you think?
>>
>> James.
>>
>>
>>
>>
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>>
>>
> 
> 
> 

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