Discussion List Archives

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: CONFORMANCE [was Re: Survey of available CIF software and

  • To: Multiple recipients of list <comcifs-l@iucr.org>
  • Subject: Re: CONFORMANCE [was Re: Survey of available CIF software and
  • From: Nick Spadaccini <nick@cs.uwa.edu.au>
  • Date: Mon, 4 Dec 2000 01:17:46 GMT
On Fri, 1 Dec 2000, Peter Murray-Rust wrote:

> quasi-pathological examples. For example, which of the following are valid 
> CIFs (syntax only)
> <empty file>


> data_


> data _X _ ""

depends on context. If what preceded data is a dataname, then data is
value, followed by a valid data name (_X), then an invalid data name or
data value (_) - definitely an error and now the parser would be thrown
into confusion, what would happen would depend on your recovery process
from the previous error.

> data_foo _foo O5'


> data_foo _foo 'O5''


> data_A data_B

invalid. A named data block must have at least one data item (name and

> data_A data_a

As above, plus as there is no case sensistivity (I believe this is true
for CIF also) you have duplicate data block names.

> data_A loop_ _a _b

Depends on what follows. If nothing, you should throw an exception. How
you recover is a matter of choice. Some would issue a fatal and terminate.
On the otherhand if this was followed by a block terminator like, data_ or
loop_ (since you can't have nested loops) then the recovery may be, assume
the data is missing and continue.

> data_A loop_ a_ b_ 1 2 3

As above. You can't really tell what to do unless you know the context.
However you do have values which are NOT a multiple of the names in the
loop definition.



Dr Nick Spadaccini
Department of Computer Science &            voice: +(61 8) 9380 3452
Software Engineering                          fax: +(61 8) 9380 1089
University of Western Australia              
CRAWLEY, Perth,  WA  6009                  email: nick@cs.uwa.edu.au
AUSTRALIA                                 w3: www.cs.uwa.edu.au/~nick

Reply to: [list | sender only]
International Union of Crystallography

Scientific Union Member of the International Council for Science (admitted 1947). Member of CODATA, the ICSU Committee on Data. Member of ICSTI, the International Council for Scientific and Technical Information. Partner with UNESCO, the United Nations Educational, Scientific and Cultural Organization in the International Year of Crystallography 2014.

ICSU Scientific Freedom Policy

The IUCr observes the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to such factors as ethnic origin, religion, citizenship, language, political stance, gender, sex or age, in accordance with the Statutes of the International Council for Science.