Search found 38 matches

by jamesrhester
Thu Aug 08, 2013 4:21 am
Forum: CIF dictionary namespace conventions
Topic: Mixed-discipline data CIFs
Replies: 10
Views: 94207

Re: Mixed-discipline data CIFs

So in practice Solution 4 should work as follows: Programmer A wishing to emit CIF data files that include moon surface temperatures from the 'astronomy' discipline together with (IUCr dataname) chemical structures found on that moon would create an adapter dictionary that e.g. prefixes all astronom...
by jamesrhester
Fri Jul 19, 2013 7:10 am
Forum: CIF dictionary namespace conventions
Topic: Mixed-discipline data CIFs
Replies: 10
Views: 94207

Re: Mixed-discipline data CIFs

Just to pick up on one of Herb's points: The cost of the prefix solution for pure IUCr CIF files is simple: parse, recognize and discard IUCR:: prefixes. Life only becomes interesting when the first mixed use of tags from some other discipline are encountered in an otherwise pure IUCr CIF. If we hav...
by jamesrhester
Fri Jul 19, 2013 6:43 am
Forum: CIF dictionary namespace conventions
Topic: Mixed-discipline data CIFs
Replies: 10
Views: 94207

Re: Mixed-discipline data CIFs

If I understand Herbert's position correctly, the use of mixed-discipline CIFs is inevitable, and so we should make sure that we can handle this use-case now rather than when it is too late. I suspect that Herbert is correct in this prediction. The single problem presented by mixed-discipline CIFs i...
by jamesrhester
Thu Jul 18, 2013 10:13 am
Forum: CIF dictionary namespace conventions
Topic: Mixed-discipline data CIFs
Replies: 10
Views: 94207

Mixed-discipline data CIFs

This post continues on from a discussion on COMCIFS in which it was proposed that mixed-discipline data CIFS be allowed. Below I rehearse the arguments against allowing tags from different disciplines to be used in a single datafile. (1) By definition, a discipline does not coordinate its namespace ...
by jamesrhester
Fri Feb 08, 2013 6:47 am
Forum: CIF Application Programming Interface
Topic: Draft API specification
Replies: 7
Views: 42737

Re: Draft API specification

Providing for case-insensitive comparison of Unicode strings used as item, data block, and save frame names is non-trivial, and the CIF2 spec changes don't really address the question. One must consider that case conversion is not unambiguously defined outside the ASCII set, and one must also consi...
by jamesrhester
Wed Feb 06, 2013 6:22 am
Forum: CIF Application Programming Interface
Topic: Draft API specification
Replies: 7
Views: 42737

Re: Draft API specification

I'm quite pleased that we've both had an independent go at thinking up an API, as we are likely to quickly triangulate any design issues. We may also drag some lurkers into the discussion. In general I think alternative 2 can be characterised as an admirably economical set of functions that fulfill ...
by jamesrhester
Mon Feb 04, 2013 7:35 am
Forum: CIF Application Programming Interface
Topic: Draft API specification
Replies: 7
Views: 42737

Draft API specification

Below I go through the exercise of writing out explicit specifications for CIF API functions. Consider the string 'cif_' to be prepended for namespace purity. The general scheme is to model the ciffile as a set of datablocks, each with a nominated parent block. Thus arbitrarily nested save frames ca...
by jamesrhester
Mon Feb 04, 2013 1:30 am
Forum: CIF Application Programming Interface
Topic: CIF Data Model
Replies: 2
Views: 28191

Re: CIF Data Model

One significant difference between the data model posted above and the "relational datamodel" is that, for the relational datamodel, values in any given column must be drawn from the same "domain", where "domain" in this context roughly means type. The various DDL dicti...
by jamesrhester
Tue Jan 29, 2013 6:31 am
Forum: CIF dictionary namespace conventions
Topic: Formal proposal for privileged _audit.domain dataname
Replies: 0
Views: 21969

Formal proposal for privileged _audit.domain dataname

To be submitted to COMCIFS together with the namespace policy. Please comment - I have speculatively added a policy for dataname scope at the end. Proposal for a new dataname to support a CIF namespace mechanism Background We wish to build some sort of namespace mechanism into CIF so that other comm...
by jamesrhester
Tue Jan 29, 2013 5:35 am
Forum: CIF dictionary namespace conventions
Topic: The namespace problem and a possible solution
Replies: 8
Views: 103268

Re: The namespace problem and a possible solution

I have just addressed the issue of the domain of embedded save frames in a separate post, found here.