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

Just to simply the menu of choice, I'll change my vote to 4096.  -- 
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 Thu, 19 Nov 2009, David Brown wrote:

> I have no strong views on line length, but the arrguments for keeping them
> seem a little stronger than those for abolishing them.� I have no views at
> all on how long the lines should be other than to note that Acta Cryst.
> programs get upset if there are more than 80 characters in a line.
> 
> David
> 
> 
> 
> James Hester wrote:
> 
> We should resolve the Fortran line length issue as I think we've got
> enough information on the table - could those who haven't indicated
> their preference please vote either
> 
> (1) CIF2 should have a maximum line length specified or
> (2) no line length should be specified.
> 
> For bonus points, you can indicate what this length should be.
> 
> So (including Nick's recent email) I count the votes as:
> 
> (1) Herbert (>=2048), Nick (2048), James (4096)
> (2) Joe
> 
> I've added my vote to the fixed line length simply because I accept
> Herbert's argument that legacy Fortran programs are actually important
> in the crystallographic world, and a restriction on line length does
> not impose a burden on CIF readers.  It also imposes a bit of
> discipline on CIF writers and helps to produce a readable file.
> 
> On Fri, Nov 13, 2009 at 3:47 AM, Joe Krahn <[email protected]> wrote:
> 
> Nick Spadaccini wrote:
> 
> On 3/11/09 12:53 AM, "Joe Krahn" <[email protected]> wrote:
> 
> Herbert,
> I am only suggesting that maintained Fortran code ought to be able to
> utilize F2003 STREAM I/O, supported by current versions of GFortran,
> Intel Fortran and Sun Fortran.
> 
> Of course, I probably am not considering all of the issues. STREAM I/O
> avoids the need for a fixed maximum record length, but even the newest
> Fortran compilers have very limited UTF-8 support. Even with STREAM I/O,
> it is not trivial to count trailing blanks as significant.
> 
> Maybe the biggest problem is UTF-8. IMHO, it makes sense for UTF-8 to be
> an optional encoding, rather than just declaring CIF2 is all UTF-8. This
> 
> Not sure what you gain by doing this. If it is pure ASCII only then the
> declaration of UTF-8 inhibits nothing, since ASCII is a subset. If it is not
> pure ASCII, then it needs to be UTF-8. I can't see how knowing in advance
> that it is a subset of UTF-8 or possibly the full set of UTF-8 gives you
> anything.
> 
> cheers
> 
> Nick
> 
> A compiler/language not aware of UTF-8 could avoid errors by rejecting
> CIF files that contain UTF-8. However, I think the approach being taken
> is just to allow implementations to restrict usage, rather than put it
> in the specifications. For example, the plan seems to be that
> DDL/dictionary definitions will be used to avoid UTF-8 in data names,
> where it is most likely to be a problem. So, you are right: there is no
> reason for the CIF2 syntax to make UTF-8 optional when the dictionaries
> can restrict characters to the ASCII subset.
> 
> The other potential legacy issues I know of are fixed maximum line
> lengths, and significant trailing blanks. Dictionary definitions cannot
> avoid these. It might be possible to take a similar approach, by
> avoiding them by implementation conventions rather than making it part
> of the spec. If these are only going to be an issue for a few more
> years, it would avoid having to make another syntax change in the near
> future.
> 
> My main interest here is to avoid incompatible implementations. I also
> think that Fortran, and any other line-oriented I/O software, should be
> able to do stream-oriented I/O in the near future.
> 
> Joe
> 
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> 
>
> 
> 
> 
> 
> 
>
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