From: Ralph Hartley (hartley_at_aic.nrl.navy.mil)
Date: Fri Feb 16 2001 - 20:19:34 CET
Received: (from mdom_at_localhost) by karto.ethz.ch (8.9.3/8.9.3/SuSE Linux 8.9.3-0.1) id UAA21527 for cavexml-outgoing; Fri, 16 Feb 2001 20:16:11 +0100 Received: from sun0.aic.nrl.navy.mil (sun0.aic.nrl.navy.mil [132.250.84.10]) by karto.ethz.ch (8.9.3/8.9.3/SuSE Linux 8.9.3-0.1) with ESMTP id UAA21523 for <cavexml_at_cartography.ch>; Fri, 16 Feb 2001 20:16:10 +0100 Received: from aic.nrl.navy.mil (pc31.aic.nrl.navy.mil [132.250.84.181]) by sun0.aic.nrl.navy.mil (8.9.3+Sun/8.9.3) with ESMTP id OAA05220 for <cavexml_at_cartography.ch>; Fri, 16 Feb 2001 14:16:15 -0500 (EST) Message-ID: <3A8D7D46.7030109@aic.nrl.navy.mil> Date: Fri, 16 Feb 2001 14:19:34 -0500 From: Ralph Hartley <hartley_at_aic.nrl.navy.mil> User-Agent: Mozilla/5.0 (X11; U; Linux 2.2.16-22 i686; en-US; m18) Gecko/20010124 X-Accept-Language: en To: cavexml_at_cartography.ch Subject: Re: Required ability of software? none References: <Pine.LNX.4.30.0102121858320.1520-100000_at_r-schuster.de> <3A8848B4.9020704_at_aic.nrl.navy.mil> <3A8A1BA7.7F781E6E_at_xmission.com> <3A8BDDB8.1070106_at_aic.nrl.navy.mil> <3A8C07DF.5020609_at_europa.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-cavexml_at_karto.baug.ethz.ch Precedence: bulk Reply-To: cavexml_at_cartography.ch
Garry Petrie wrote:
> Ralph Hartley wrote:
>
>>
>>
>> How hard are you willing to work to preserve data you don't care
>> about? How hard are you willing to work to remove data you don't
>> care about? If the answer to both questions is "not very", we
>> (everyone) could win.
>>
>>> If you don't want to loose data don't send it through anything that
>>> doesn't preserve what you want.
>>
>> But first, make sure there *is* something that preserves what you
>> want. That is the goal of CaveXML.
>
To be clear, the "you" in this sentence is the user, not the programer.
>>
> What to do, what to do about optional data, XYZ, spanning trees,
> station and shot IDs. I think this information can be discarded in an
> import-export process, even in which the user over writes the original
> file.
If the user wants to discard such data, that's ok. Presumably he knows
what he wants. But to useable, a conversion program MUST ALLOW all data,
not just what it understands, to be preserved through a round trip.
> User beware. The CaveXML description some how has to define the
> required vs optional data. If the user wants to save the optional
> data, either always use the same software that produced it, save it to
> different file names or use RCS.
Required data is what the program can't do without, not what the program
needs to preserve. If the user wants to delete something, even
"everything the program doesn't understand" he can. For a program to
force him to, without a good reason (CaveXML is an attempt to eliminate
any reason) puts an unjustified restriction on what can be done. If
everyone puts up "one way street" signs, you end up like some old cities
(Point at a map and ask policeman "How do I get here?", he says "No!").
The other "solutions" don't do what needs to be done. Always using the
same software assumes there is one program that does everything I need.
If there was I wouldn't need a transfer format at all.
Does every program have to save each type of data in a different file?
If not, how can my program separate just the data your program doesn't
preserve, without knowing what that is? Remember, other programs may
have very different ideas of what is "required".
> Ultimately, we can not consider all cases and deal with them effectively.
There are only two cases. Data the program understands, which it
presumably does the right thing to, and data the program doesn't
understand, which it must leave the hell alone!
> You see those types of warnings all the time when converting file
> types, e.g. in MS Word.
I wouldn't exactly call that a model to be emulated! Unless, of course,
you want to make lots of money by forcing everyone to buy an upgrade
without improving your product first (warning! doesn't work for non 800
lb gorillas).
Ralph Hartley
This archive was generated by hypermail 2b30 : Thu Mar 01 2001 - 18:00:01 CET