<div dir="ltr"><div class="gmail_quote"><div>I really hope I didn't miss some connections in this long thread, but...</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
The real point is that the VODML-ID "coords:TimeFrame.timescale” could be "coords:a.b" according to the VO-DML standard - there is no connection between the vodml-id and the name of the model element as defined in the standard - I want to make the connection, and once the connection is made, the VODML-ID is redundant as it can be generated from the model structure.<br></blockquote><div><br></div><div>If I understand Paul's point correctly, I'd like to point out that the reason for having the entire vodml-id was to make sure that a model's element could always be identified unambiguously in any context, in particular when extending models. VODML allows data providers to extend a type (section 4.6.1). When they do, parsers need a way to identify fields in an unambiguous way, which includes mapping them to the model document where they are defined.</div><div><br></div><div>In that sense, the vodml-id becomes redundant not only if one makes the connection with the name, but also if a mapping scheme defines a way to represent extensions that provides that unambiguous mechanism. If an instance is of type <custom:MyType> (which extends standard:Type), one would have attributes identified by <custom:MyType.myAttribute> and <standard:Type.attribute> within that instance, which the parser could map to the respective definitions without having to rely on any heuristics or complex logic.</div><div><br></div><div>If one has a <custom:MyType> instance with attributes <myAttribute> and <attribute> the parser wouldn't really know where to look them up unless the connection between <custom:MyType> and <standard:Type> is made explicit in the serialization markup. And even in that case, since the parser doesn't know whether myAttribute is defined in custom: or in standard: it'll have to try both.</div><div><br></div><div>People have argued in the past that inheritance requires parsers to have complex type algebra, which may be true depending on the use case and of the mapping strategy. However, extensibility was one of the main requirements for VODML. A mapping strategy can minimize that effort by identifying an instance as both custom:MyType and standard:Type. And since we recommend vodml-ids to be generated algorithmically, a parser could decide to ignore model definitions completely, and parse the vodml-ids to display the attribute names, which would be human-readable. Other parsers would be interested in the unambiguous identification of attributes to provide richer context-dependent features to client software.</div><div><br></div><div>A change could be made to the VODML spec to make the vodml-id generation a requirement rather than a preference, by promoting Appendix C to normative state. And while I remember believing that both approaches (full vodml-id or just name) would work, as long as the mapping provides enough markup to make the references unambiguous, I did have a preference for the full vodml-id for two reasons: 1. because explicit is better than implicit and 2. because it is more future-proof.</div><div><br></div><div>A reference to a full vodml-id is always going to unambiguously identify a single element, like a URI. I can go from custom:MyType.myAttribute to myAttribute and from standard:Type.attribute to attribute, but I can't go from myAttribute to custom:MyType.myAttribute without some effort parsing definition documents.</div><div><br></div></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr" style="margin-left:0pt" align="left"><table style="border:none;border-collapse:collapse"><colgroup><col width="445"><col width="275"></colgroup><tbody><tr style="height:90pt"><td style="border-width:1pt;border-style:solid;border-color:rgb(255,255,255);vertical-align:top;padding:5pt;overflow:hidden"><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><span style="font-size:9.5pt;font-family:Arial;color:rgb(34,34,34);background-color:transparent;font-weight:700;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Omar Laurino (he/him)<br></span></p><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><span style="font-size:9.5pt;font-family:Arial;color:rgb(34,34,34);background-color:transparent;font-weight:700;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Smithsonian Astrophysical Observatory<br></span></p><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><span style="font-size:9.5pt;font-family:Arial;color:rgb(0,0,0);background-color:transparent;font-weight:700;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Center for Astrophysics | Harvard & Smithsonian</span></p><p dir="ltr" style="line-height:1.2;margin-top:0pt;margin-bottom:0pt"><span style="font-size:9.5pt;font-family:Arial;color:rgb(34,34,34);background-color:transparent;font-weight:400;font-style:normal;f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