Subj : Net Development
To   : Jan Vermeulen
From : Jasen Betts
Date : Sun Jan 05 2003 10:16 pm

Hi Jan.


04-Jan-03  Jan Vermeulen wrote to Scott Little


 JV> How can you be 100% sure that you will get the old data back when
 JV> generaing an SLF list from the XML data

Is it desirable to get 100% the same data back anyway?

things like the ordering of the flags or the method used to publish
internet address aren't critical and some systems work better with
one form and others with a different form.

 mb>> Of cource we have to see to it that everything we change also can
 mb>> be provided in a backward compatible format for the sysops.

 JV> Ok, the intention is there. But how sure can you be that not even
 JV> one byte will get lost or damaged in the operation

One way is to prove the software and specification mathematically,
but first a design is needed.

 JV>>> How can you be 100% sure that you will get the old data back
 JV>>> when generaing an SLF list from the XML data?

 sl>> You can't, but that's dependant on the broken-ness of the input
 sl>> SLF.  Theoretically, the SLF -> XML conversion will only extract
 sl>> "known good" data, leaving the rest as undecipherable nonsense
 sl>> which XML native programs will ignore, but will be restored when
 sl>> converted back to SLF.

 JV> This implies that an XML list generated from the nodelist at one
 JV> place will not yield the same nodelist somewhere else. I don't
 JV> like that

why?  as long as it contains the apropriate information does it matter,


when the extractor has to produce SLF for that nodeline it cant know how
the line was originallt organised, but it can express the information in a
sensible way.

suppose this goes in:

,100,213.84.184.65,Wormerveer,Jan_Vermeulen,31-75-6400418,9600,CM,XA,V32B
   ,V42B,V34,VFC,V120L,V120H,X75,IBN,PING,U,ENC

if it comes out like this:

,100,213.84.184.65,Wormerveer,Jan_Vermeulen,31-75-6400418,9600,XA,V32B,
   V34,V42B,VFC,V120L,V120H,X75,IBN,PING,CM,U,ENC

does it really matter?

 -=> Bye <=-

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