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Re: [ddlm-group] CIF header

So, to try to reduce this to two simply choices:

For both choices, we are discussing quoted stings delimited by

   1.  The single quote character '\''
   2.  The double quote character '"'
   3.  The newline-semicolon digraph "\n;"
   4.  The treble single quoted trigraph "'''"
   5.  The treble double quotes trigraph "\"\"\""

In the first two cases the string may not contain a new-line character In 
the last three cases the string may contain new-line characters

In all cases, the processing of a quotes string ceases when an unprotected 
terminal quoting character, digraph or trigraph is encountered

The two proposals have to do with the handling of the protection of a 
terminal quoting chacater, digraph or trigraph.

Proposal 1:  The string delivered to the application will be literally the 
string of characters starting from the first character after the initial 
quoting character, digraph or trigraph through the last character prior to 
the first unprotected terminal quoting character, digraph or trigraph, not 
including the initial or terminal quoting character, digraph or trigraph. 
An unprotected reverse-solidus will protect the following character for 
interpretation as a reverse solidus, or as a terminal quoting character or 
as a member of a terminal digraph or as a member of a terminal trigraph, 
but will be included in the string delivered to the application. Thus 
"ab\"cd" and 'ab\"cd' would return the same string (ab\"cd) to the 
application

Proposal 2. The string delivered to the application will be literally the 
string of characters starting from the first character after the initial 
quoting character, digraph or trigraph through the last character prior to 
the first unprotected terminal quoting character, digraph or trigraph, not 
including the initial or terminal quoting character, digraph or trigraph 
and not including any reverse-solidus protecting a terminal quoting 
character or protecting any individual character in a terminal digraph or 
trigraph.  Any reverse-solidus will protect the following character for 
interpretation as a a terminal quoting character or as a member of a 
terminal digraph or as a member of a terminal trigraph, and will be 
removed from the string delivered to the application. Thus "ab\"cd" and 
'ab\"cd' would return the two different strings (ab"cd vs. ab\"cd) to the 
application

Please check whether I have presented the substance of the difference in 
approaches fairly, and if so, let us please just have straw vote and 
finish this.

I favor proposal #1.

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
                  yaya@dowling.edu
=====================================================

On Mon, 23 Nov 2009, Nick Spadaccini wrote:

> Agree to
> #<something>CIF_2.0
>
> <something> is whatever character sequence people are happy with.
>
> <something>=\# seems reasonable enough.
>
> Don't see we need for the _ between CIF and 2.0, but agnostic about it. I am
> assuming there must be an existing CIF_1.1 magic sequence in use - though I
> don't recall any formal specification for it.
>
>
> On 23/11/09 1:32 PM, "James Hester" <jamesrhester@gmail.com> wrote:
>
>> I agree with Brian's suggestion.  Can other participants also indicate
>> their agreement or alternative suggestions?
>>
>> James.
>>
>> On Fri, Nov 20, 2009 at 11:15 PM, Brian McMahon <bm@iucr.org> wrote:
>>>>>> Is there a reason why it can't be #!, to make it consistent with other
>>>>>> *nix
>>>>>> based directives.
>>>
>>> As James says, #! is normally understood by Unix shells to specify
>>> an appropriate shell interpreter, not quite what we're aiming for here.
>>>
>>> A characteristic initial set of bytes (file 'magic') is often used
>>> by GUI file managers and other generic file-handling software to
>>> associate icons or applications (in association with, or sometimes
>>> competing against, the use of a filename extension). We use this
>>> approach to identify the type of file uploaded in our submission
>>> system. It's useful for that initial byte sequence to be (a) short
>>> to facilitate rapid scanning, (b) specific to an individual file type.
>>> For that reason we suggested for CIF 1.1 the magic string
>>>      #\#CIF_1.1
>>> For CBF it is
>>>      ###CBF: VERSION
>>>
>>> I recommend #\#CIF_2.0 to be consistent with version 1.1 and so that
>>> generic file magic handling can map all #\#CIF_ strings to files of type
>>> "cif". (A sophisticated file manager could extend the scan to allow for
>>> different icons to be associated with version 1.1 and version 2 CIFs.)
>>> It seems a pity from the viewpoint of neatness that the CIF and CBF
>>> magic strings aren't more similar in structure.
>>>
>>> Brian
>>>
>>> On Fri, Nov 20, 2009 at 02:09:56PM +0800, Nick Spadaccini wrote:
>>>>
>>>> We don't need an extra character, a single hash would suffice, but I guess
>>>> an extra character my uniquely identify it as the CIF header to a parser,
>>>> rather than it as just a comment. An extra character also moves you away
>>>> from an ordinary comment which is smart, to a smart comment which has its
>>>> own unique tag. I am NOT a fan of smart comments, or comments which can be
>>>> smart, but they seem to be to modus operandi of many systems.
>>>>
>>>> On 20/11/09 1:59 PM, "James Hester" <jamesrhester@gmail.com> wrote:
>>>>
>>>>> Wouldn't this cause a UNIX-style OS to try to execute 'CIF2' if
>>>>> someone accidentally typed the filename in a command context?  This is
>>>>> not a huge problem in that it will otherwise attempt to execute
>>>>> 'data_xxxx', and only if the file is executable.
>>>>>
>>>>> I guess I don't understand why we need an extra character after the
>>>>> hash.  If we really do need an extra character, why not just another
>>>>> hash?
>>>>>
>>>>> On Mon, Nov 9, 2009 at 7:30 PM, Nick Spadaccini <nick@csse.uwa.edu.au>
>>>>> wrote:
>>>>>> On 30/10/09 11:47 PM, "Joe Krahn" <krahn@niehs.nih.gov> wrote:
>>>>>>
>>>>>>> A directive embedded in an initial comment really does make sense,
>>>>>>> because it is irrelevant once the correct parser is selected. It might
>>>>>>> make sense to add a specific 2nd character, similar to the POSIX shell
>>>>>>> #!. For example, the STAR format could define an initial line beginning
>>>>>>> with #% as parsing directive rather than just a plain comment. That
>>>>>>> makes the abuse of a comment line as a bit less of a hack.
>>>>>>
>>>>>> Is there a reason why it can't be #!, to make it consistent with other
>>>>>> *nix
>>>>>> based directives.
>>>>>>
>>>>>> cheers
>>>>>>
>>>>>> Nick
>>> _______________________________________________
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>>>
>>
>>
>
> 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: Nick.Spadaccini@uwa.edu.au
>
>
>
>
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