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Re: [ddlm-group] CIF-2 changes

As the syntax that we have been developing now stands, the only reason
for not using square brackets is so that it will be possible to
correctly parse a CIF in which a space is accidentally missing between
a dataname and a bracketed list.  This seems to me to be a pretty
minor reason to fiddle with the bracket syntax, but having got that
off my chest I don't have any objections to the revised syntax.

NB I believe Nick would like to drop the concept of tuples in DDLm and
dREL altogether, with which I also agree.

On Thu, Oct 29, 2009 at 10:31 PM, Herbert J. Bernstein
<[email protected]> wrote:
> I have no objection to Nick's approach. �I would suggest a straw vote as
> soon as possible, so that we can have move forward on coding. �So to be as
> specific as possible, here is what I think Nick is proposing:
>
> � 1. �All the bracketed constructs in a CIF be delimited by {}:
> � � � �Lists: �{ ..., ... }
> � � � �Tuples: { ..., ... }
> � � � �Arrays: { ..., ... }
> � � � �Tables: { key:value, key:value } with the distinctions among them
> made primarily by the type specifications. Note that the key in a table
> should be a quoted string.
>
> � 2. �That array dimensions in a CIF also be delimited by {} as in
> {3} or {3,4}
>
> � 3. �That the same changes be made in dREL
>
> (Nick, did I get that right?)
>
> I can work with all of the above, and I suspect Nick is right about the
> long-term value of consistency here, and reasonably strong typing does
> tend to reduce coding errors. �What do other people think?
>
> 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
> � � � � � � � � �[email protected]
> =====================================================
>
> On Wed, 28 Oct 2009, Nick Spadaccini wrote:
>
>> The move away from [] lists to {} lists (thus overlapping with {}
>> associative arrays) had to do with cleaning up the syntax under CIF-2.
>>
>> There are legacy issues with existing CIF data names with embedded [] which
>> meant that using [ to initiate a list would come unstuck.
>>
>> Accordingly to simplify matters and to move forward, I proposed using {} to
>> define lists or associative arrays. The complication to the parser is that
>> you must start to look inside the object to determine which it is.
>>
>> That is CIF. dREL is a different matter but consistency is a good thing, so
>> that it makes sense to keep the syntax the same as a CIF data file. Hence
>> your transcription of the dREL code is correct. It makes my work a lot more
>> difficult of course because until now I just called up a Python parser to
>> handle almost all of dREL.
>>
>> Such is life.
>>
>>
>> On 25/10/09 10:24 PM, "Herbert J. Bernstein" <[email protected]>
>> wrote:
>>
>>> Dear Colleagues,
>>>
>>> � �Please take a look at the dictionaries I have drafted at
>>>
>>> � �http://vcif.sf.net/cif2_dicts
>>>
>>> and tell me if I am on the right track in trying to convert to CIF-2
>>> format dictionaries. �I have taken all the August 2008 () style tuples in
>>> the upper level and converted them to October 2009 CIF-2 {} style lists.
>>> I have not changed any array dimension specifications, e.g. [*], nor the
>>> innards of any methods.
>>>
>>> � �Questions:
>>>
>>> � �1. �Should the dimensions be changed, e.g. from [3] to {3}?
>>> � �2. �Should there be any changes in dREL methods themselves?
>>>
>>> For example consider:
>>>
>>> ======
>>> save_function.SymEquiv
>>> � � �_definition.id � � � � � � �'function.SymEquiv'
>>> � � �_definition.update � � � � � 2007-10-11
>>> � � �_description.text
>>> ;
>>> � � � The function
>>> � � � � � � � � � � � xyz' = �SymEquiv( symop, symcat, xyz )
>>>
>>> � � � returns a fractional coordinate vector xyz' which is input vector
>>> � � � xyz transformed by the input symop 'n_pqr' applied to the symmetry
>>> � � � equivalent matrix extracted from the category symcat.
>>> ;
>>> � � �_name.category_id � � � � � �function
>>> � � �_name.object_id � � � � � � �SymEquiv
>>> � � �_type.purpose � � � � � � � �Assigned
>>> � � �_type.container � � � � � � �Array
>>> � � �_type.contents � � � � � � � Real
>>> � � �_type.dimension � � � � � � �[3]
>>> � � � loop_
>>> � � �_method.purpose
>>> � � �_method.expression
>>> � � � Evaluation
>>> ;
>>> � � � Function SymEquiv( c :[Single, Symop], � �# symop string n_pqr
>>> � � � � � � � � � � � � �l :[Category, Tag], � �# loop of symmetry matrices
>>> � � � � � � � � � � � � �x :[Array, Real] � �) �# fract coordinate vector
>>> � � � {
>>> � � � � � � � s = l [ SymKey( c ) ]
>>>
>>> � � � � � � � SymEquiv = s.R * x + s.T + SymLat( c )
>>> � � � }
>>> ;
>>> � � �save_
>>> ======
>>>
>>> Should that remain the same, or should it be as follows
>>>
>>> ======
>>> save_function.SymEquiv
>>> � � �_definition.id � � � � � � �'function.SymEquiv'
>>> � � �_definition.update � � � � � 2007-10-11
>>> � � �_description.text
>>> ;
>>> � � � The function
>>> � � � � � � � � � � � xyz' = �SymEquiv( symop, symcat, xyz )
>>>
>>> � � � returns a fractional coordinate vector xyz' which is input vector
>>> � � � xyz transformed by the input symop 'n_pqr' applied to the symmetry
>>> � � � equivalent matrix extracted from the category symcat.
>>> ;
>>> � � �_name.category_id � � � � � �function
>>> � � �_name.object_id � � � � � � �SymEquiv
>>> � � �_type.purpose � � � � � � � �Assigned
>>> � � �_type.container � � � � � � �Array
>>> � � �_type.contents � � � � � � � Real
>>> � � �_type.dimension � � � � � � �{3}
>>> � � � loop_
>>> � � �_method.purpose
>>> � � �_method.expression
>>> � � � Evaluation
>>> ;
>>> � � � Function SymEquiv( c :{Single, Symop}, � �# symop string n_pqr
>>> � � � � � � � � � � � � �l :{Category, Tag}, � �# loop of symmetry matrices
>>> � � � � � � � � � � � � �x :{Array, Real} � �) �# fract coordinate vector
>>> � � � {
>>> � � � � � � � s = l { SymKey( c ) }
>>>
>>> � � � � � � � SymEquiv = s.R * x + s.T + SymLat( c )
>>> � � � }
>>> ;
>>> � � �save_
>>> ======
>>>
>>> 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
>>> � � � � � � � � � [email protected]
>>> =====================================================
>>>
>>> _______________________________________________
>>> ddlm-group mailing list
>>> [email protected]
>>> http://scripts.iucr.org/mailman/listinfo/ddlm-group
>>
>> cheers
>>
>> Nick
>>
>> --------------------------------
>> Associate Professor N. Spadaccini, PhD
>> School of Computer Science & Software Engineering
>>
>> The University of Western Australia � �t: +61 (0)8 6488 3452
>> 35 Stirling Highway � � � � � � � � � �f: +61 (0)8 6488 1089
>> CRAWLEY, Perth, �WA �6009 AUSTRALIA � w3: www.csse.uwa.edu.au/~nick
>> MBDP �M002
>>
>> CRICOS Provider Code: 00126G
>>
>> e: [email protected]
>>
>>
>>
>>
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