[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Reply to: [list | sender only]
Re: [ddlm-group] Relationship of CIF2 to legacy platforms
- To: Group finalising DDLm and associated dictionaries <ddlm-group@iucr.org>
- Subject: Re: [ddlm-group] Relationship of CIF2 to legacy platforms
- From: James Hester <jamesrhester@gmail.com>
- Date: Thu, 19 Nov 2009 13:34:45 +1100
- In-Reply-To: <4AFC3C0B.7060404@niehs.nih.gov>
- References: <C71DF6D4.12389%nick@csse.uwa.edu.au><4AFC3C0B.7060404@niehs.nih.gov>
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 <krahn@niehs.nih.gov> wrote: > Nick Spadaccini wrote: >> >> >> On 3/11/09 12:53 AM, "Joe Krahn" <krahn@niehs.nih.gov> 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 > > _______________________________________________ > ddlm-group mailing list > ddlm-group@iucr.org > http://scripts.iucr.org/mailman/listinfo/ddlm-group > -- T +61 (02) 9717 9907 F +61 (02) 9717 3145 M +61 (04) 0249 4148 _______________________________________________ ddlm-group mailing list ddlm-group@iucr.org http://scripts.iucr.org/mailman/listinfo/ddlm-group
Reply to: [list | sender only]
- Follow-Ups:
- Re: [ddlm-group] Relationship of CIF2 to legacy platforms (David Brown)
- Re: [ddlm-group] Relationship of CIF2 to legacy platforms (Nick Spadaccini)
- References:
- Re: [ddlm-group] Relationship of CIF2 to legacy platforms (Nick Spadaccini)
- Re: [ddlm-group] Relationship of CIF2 to legacy platforms (Joe Krahn)
- Prev by Date: Re: [ddlm-group] CIF-2 changes
- Next by Date: Re: [ddlm-group] Relationship of CIF2 to legacy platforms
- Prev by thread: Re: [ddlm-group] Relationship of CIF2 to legacy platforms
- Next by thread: Re: [ddlm-group] Relationship of CIF2 to legacy platforms
- Index(es):