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Re: [ddlm-group] THREAD TRIPLE QUOTES - Specification

On 11/09/09 10:06 PM, "Herbert J. Bernstein" <yaya@bernstein-plus-sons.com>
wrote:

> The main value of the treble quoted string is that it allows a much
> neater presentation of examples of chunks of CIFS and text in which
> presenting such information within semi-colon quoted strings gets
> somewhat confusing.
> 
> For this reason, I would suggest that the most important test of
> Nick's suggestions would be how faithfully a semi-colon delimited
> example could be included with _no_ added or subtracted characters,
> so that people reading dictionaries by eye will reproduce those
> examples correctly.

Yes if treated as a raw string you can faithfully represent a semi-colon
delimited text block. BUT you CAN'T faithfully represent a CIF that has
itself a triple quote string. Same internal problem that exists trying to do
it within semi-colon strings. But CIF within a string is only one thing.
What about JMol scripts within a string, probably no problem. What about
SBEVSL, possibly no problem. Now what about a Python script - now we can see
the problems.  

However by adding and removing a trailing space after every " encountered we
are able to represent everything.

> For that reason, I hope we can stay as close to """ and ''' delimiting
> truly raw data as possible.

I have purposefully only referred to """ because I will argue there is no
need to introduce yet another delimiting syntax. The """ will cover
everything.

I introduced the rap around simply to have one string construct that
formally allows for it and requires it to be handled. Do date all such
beaviours are conventions, not formally specified as a requirement.

> 
> On Fri, 11 Sep 2009, Nick Spadaccini wrote:
> 
>> Our last discussion on the implementation of triple quoted strings resulted
>> in much to-ing and fro-ing and in the end the conclusion was that its
>> behaviour was to be identical to the semi-colon delimited strings. I
>> preferred a greater degree of parsing of the string but this was not
>> popular.
>> 
>> Now our illustrious chair, who sits next to me now, asks the question "what
>> is the point of the triple quoted string", to which I can only shrug my
>> shoulders. The triple quote string will be useful for containing strings
>> that include ", ' and ; (in the first character in a record). They will of
>> course fail when you attempt to include the sequence """. Hence they are no
>> different to a ; delimited string that cannot include a ; as the first
>> character of a line.
>> 
>> Here is a suggestion. The triple quote string (delimited by """) will treat
>> its contents a raw, except that
>> 
>> (a) When writing the string, ALL quotes contained within will have a space
>> inserted immediately after the " character. This will allow the triple quote
>> to be contained within the string by breaking the sequence with spaces so
>> the tokeniser is not fooled in to terminating the string. Clearly the
>> reverse operation is required in reading the string. I this way is is
>> possible to include all manner of text, markup and programming scripts
>> within a triple quoted string.
>> 
>> (b) We will formally accept in this string the "eliding" of the newline
>> character. Hence a reverse solidus (\) immediately prior to the record
>> terminating character(s) will imply the \ and the record terminating
>> characters are deleted from the stream, and the next line is wrapped around.
>> 
>> To allow for the odd case when one want's to literally include the \ and the
>> record terminating character(s) in the string then the required \ will be
>> elided.
>> 
>> In parsing the contents of a string the only things required are
>> (1) delete one of the spaces after every "
>> (2) treat \<newline> as a wrap around
>> (3) treat \\<newline> as the raw string \<newline>
>> 
>> All other characters are left as is.
>> 
>> 
>> 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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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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