[OSM-talk] Users, contributors and developers

[Andy Robinson]

Frederik Ramm [mailto:frederik at remote.org] wrote:
>Sent: 27 April 2007 11:47 AM
>To: Andy Robinson
>Cc: 'Sebastian Spaeth'; talk at openstreetmap.org
>Subject: Re: [OSM-talk] Users, contributors and developers
>
>Hi,
>
>> Am I missing something here, if we allow the key column to take any
>> format
>> of tags separated by colons and the value column separated by
>> semicolons do
>> we not get all the flexibility we need without introducing unnecessary
>> restriction?
>
>As far as I understood, many people called for the "third column"
>because they were hoping to get rid of the colons. The colons are a
>pain to process in environments where you do not routinely have
>string operations available, e.g. XSLT transformations.
>
>The same, even more so, goes for semicolons in values; you do not
>want to have to check values for semicolons every time you use them.
>If you need a list of things, it is far, far better to somehow find a
>way to tell the database that here is a list of things, than trying
>to encapsulate the list in a string field.
>
>Extrapolating your argument into a nice little strawman, one could
>say "why do we even have keys, let us just put one big text field for
>each way, where people can then write something like
>'highway=residential,name=Brauer Blvd.,...'". Such a scheme would
>offer maximum flexiblity; one could even use that string to enter
>groupings like the one asked for by Spaetz ("highway=residential,
>(restriction=oneway,restriction_valid=8am-8pm),
>(restriction=noaccess...)"). But it would be a nightmare to work with
>that in a renderer or an editor.
>

In that case I don't see the real benefit of an extra column because there
will be many examples in the future where you would need a lot more than
just three. So I'd say keep with the two and let the power of the modern day
processor work it out from there.

Cheers

Andy

Andy Robinson
Andy_J_Robinson at blueyonder.co.uk

>Bye
>Frederik
>
>--
>Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00.09' E008°23.33'
>