[OSM-talk] Overpass turbo Has it been amended?

Roland Olbricht roland.olbricht at gmx.de
Fri Oct 24 10:59:26 UTC 2014


> > Ok, so you recommend to use QL instead of XML. Is there some feature that
> > are in QL and not in XML ?
> > The XML will be maintained for how long ?
> > and quickosm should switch from XML to QL in the short term  ?

> Currently, all features are available in both XML and QL variants, but
> the most recent additions have only been announced and documented for
> the QL language. I don't think that the XML language will be dumped
> anytime soon. Maybe Roland can tell us more about his long-term plans
> about deprecating the XML language.

Thank you for bringing up this question. Acouple of people have asked me in
personal communication, but I haven't made so far a public statement to
bring clarity.

Both languages have unlimited support.

The software is designed in such a way such that the XML syntax makes no extra
effort. In fact, the names of the statements are the names of the internal
classes, so the XML support is tightly integrated.

QL makes a little bit more effort with a dedicated parser, but that language
has a couple of advantages: It is more briefly, which simplfies to
write and publish code of it. Secondly, most programmers are nowadays familiar
with C-style syntax, so there is less learning effort.

The probably most striking aspect might be a cultural. Forced updates are
amongst the things in the software world I hate most, so I would not deprecate
things unless I'm absolutely forced to do so. The program code by design doesn't
require deprecation, so it is unlikely that I would deprecate one of the
languages soon.
 
Another issue is documentation. I'm lagging behind a lot in this regard. And
to catch up more quickly with incoming minor fixes and extensions, I would
prefer to write the documentation for QL only in the future and publish for the
XML syntax just a translation help.

Best regards,

Roland



More information about the talk mailing list