<div dir="ltr">Hi F-X,<div><br></div><div>I gave a presentation on this subject at the last IVOA interop. We at the CADC went through the same exercise with the parser just to discover that it has no future and we should direct effort elsewhere. Maybe a MOC-regions parser and encoder that could be then used for footprints?</div><div><br></div><div>The bottom line is that STC-S leaves a void that we as a community need to fill in soon. So yes, I agree that STC-S should be moved to a retired documents corner but at the same time a replacement should be put in place. I'm not sure which WG should drive this.</div><div><br></div><div>Adrian </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Nov 30, 2023 at 8:55 AM Francois-Xavier PINEAU <<a href="mailto:francois-xavier.pineau@astro.unistra.fr">francois-xavier.pineau@astro.unistra.fr</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><u></u>
<div>
<p>Hi Markus,</p>
<p>Thank you very much or your answer.<br>
<br>
I was not aware of your parser:<br>
* what do you mean by 'halfway complete'?<br>
* what about using it in astropy regions
(<a href="https://github.com/astropy/regions/issues/21" target="_blank">https://github.com/astropy/regions/issues/21</a>) ?</p>
<p>> <span>Do you have a strong reason to do that?
Several users have been asking for MOC creation from a STC-S string, and we have been
thinking to add this features to MOC Lib Rust (and hence, to MOCPy).
And:
1 - I was not aware of the subset (for geometries) defined in the TAP document (</span><span>again, </span><span>thank you);
2 - STC-S could be used as an input to create ST-MOCs, F-MOCs, ... in addition to S-MOCs.</span></p>
<p><span>There are others possibilities (STC-S based queries in QAT2S, more general STC-S parser in Aladin Lite, ...).
</span></p>
<p>> The operationally (still) relevant subset for specifying
geometries is in section 6 of TAP 1.0<br>
Grrr... I see that:<br>
* the 'frame' is mandatory in the STC-S document and optional in
TAP,<br>
* the vocabulary is not exactly the same:<br>
CART[123] vs CARTESION[123]<br>
SPHER2 vs SPHERICAL2<br>
It 's easy to support both inputs, but an option is needed in
output (to choose between the STC note and the TAP standard).<br>
<br>
</p>
<p>FWIW, I just published a first version of the Rust STC-S parser:<br>
<a href="https://github.com/cds-astro/cds-stc-rust" target="_blank">https://github.com/cds-astro/cds-stc-rust</a><br>
For non-Rust users the main interest so far may be to transform
STC-S string into JSON, back and forth.<br>
</p>
<p>> <span>Let's move that WD to the "Obsolete IVOA documents"
Since it has been asked by users, it seems that STC-S is used, right?
Do Coords and Meas offer an </span>ASCII-String<span> serialization? (Laurent?)
</span>(Maybe I am old school, but I kind of like ASCII-String
serializations)<br>
<span></span></p>
<p><br>
</p>
<p>fx<br>
</p>
<p><br>
</p>
<div>Le 29/11/2023 à 11:09, Markus
Demleitner a écrit :<br>
</div>
<blockquote type="cite">
<pre>Hi FX,
On Tue, Nov 28, 2023 at 04:58:34PM +0100, F.-X. Pineau wrote:
</pre>
<blockquote type="cite">
<pre>I am implementing a STC-S parser (in Rust, obviously) from the
WD-STC-S-1.0-20130918 document:
</pre>
<blockquote type="cite">
<pre><a href="https://www.ivoa.net/documents/STC-S/20130917/WD-STC-S-1.0-20130917.html" target="_blank">https://www.ivoa.net/documents/STC-S/20130917/WD-STC-S-1.0-20130917.html</a>
</pre>
</blockquote>
</blockquote>
<pre>Do you have a strong reason to do that? You see, I've once written a
halfway complete one (if you're interested:
<a href="https://gitlab-p4n.aip.de/gavo/dachs/-/tree/main/gavo/stc" target="_blank">https://gitlab-p4n.aip.de/gavo/dachs/-/tree/main/gavo/stc</a>), and I've
regretted it, as there is little use for it.
The operationally (still) relevant subset for specifying geometries
is in section 6 of TAP 1.0
<a href="https://ivoa.net/documents/TAP/20100327/REC-TAP-1.0.html" target="_blank"><https://ivoa.net/documents/TAP/20100327/REC-TAP-1.0.html></a>.
Even there, there's no formal specficiation, and really, nobody wants
to touch the whole mess; in our DALI discussions, there was zero
enthusiasm for moving that material into that spec (where it could
become normative). See the current DALI 1.2 WD for the sort of types
we would like to use in the future.
But, well, the TAP 1.0 STC-S subset at least is (still) in active
use.
</pre>
<blockquote type="cite">
<pre>Is the grammar wrong?
Is there an 'official/original' STC-S parser that could be used as a
reference?
Should an erratum be issued?
</pre>
</blockquote>
<pre>The document is a (fairly rough) working draft, so there wouldn't be
an erratum but a new working draft.
But nobody has touched the WD in a decade, and I don't see that
change, in particular since the underlying data model (STC 1.03) has
been superseded by Coords and Meas in the meantime.
My take would be: Let's move that WD to the "Obsolete IVOA documents"
section in the doc repo. It keeps confusing people who are actually
looking for the TAP 1.0 geometry specification.
-- Markus
</pre>
</blockquote>
</div>
</blockquote></div>