Right, sorry, indeed -- `c` is a field name.

The type fullname would be a.d in the example you showed.

The spec says (in a list of the possible ways full names can be determined):

A name only is specified, i.e., a name that contains no dots. In this case the 
namespace is taken from the most tightly enclosing schema or protocol. For 
example, if "name": "X" is specified, and this occurs within a field of the 
record definition of org.foo.Y, then the fullname is org.foo.X. If there is no 
enclosing namespace then the null namespace is used.
IMO, the spec is clear that there is no difference between specifying a 
namespace separately (e.g. "namespace": "a", "name": "b"), and specifying a 
namespace implicitly (e.g. "name": "a.b").

> On Dec 27, 2021, at 1:25 PM, Spencer Nelson <s...@spencerwnelson.com> wrote:
> 
> Trick question! "c" is a field name, not a type name, so the fullname is 
> either "a.d" or "d". Fields don't have fullnames.
> 
> But your question is still good. I don't think this is clear in the Avro 
> specification either. I asked avro-dev about this about a year ago and got no 
> response: 
> http://mail-archives.us.apache.org/mod_mbox/avro-dev/202103.mbox/%3cCAB6dobWX1=_fctgvgm-d5r17pv_69u27tdzvljmwc+aizow...@mail.gmail.com%3e
>  
> <http://mail-archives.us.apache.org/mod_mbox/avro-dev/202103.mbox/%3cCAB6dobWX1=_fctgvgm-d5r17pv_69u27tdzvljmwc+aizow...@mail.gmail.com%3e>
> 
> As I mentioned in that email, there are even more tricky cases than the one 
> you listed. What if the "a.b" schema definition is wrapped inside another 
> schema with an explicit "namespace" field? Like this:
> 
> {
>   "type": "record",
>   "name": "wrapper",
>   "namespace": "wrapping"
>   "fields": [
>     {
>       "name": "inside",
>       "type": {
>           "type": "record",
>           "name": "a.b",
>         "fields": [
>           {
>             "name": "c",
>             "type": {
>               "type": "record",
>               "name": "d",
>               "fields": []
>             }
>           }
>         ]
>       }
>     }
>   ]
> }
> 
> Now is the interior one "a.d" (since "a.b" is a fullname, so it implicitly 
> creates a namespace of "a"), or is it "wrapping.d" (since that's the first 
> explicit namespace)?
> 
> The spec just says that when a type is named with dots in it (like "a.b"), 
> then it ignores any namespaces, but it doesn't say it creates one for all 
> children. I think implementations are inconsistent in how they handle this, 
> and it needs to be cleaned up in the spec.
> 
> 
> 
> On Mon, Dec 27, 2021 at 1:53 PM Brennan Vincent <bren...@umanwizard.com 
> <mailto:bren...@umanwizard.com>> wrote:
> It is a.c
> 
> > On Dec 27, 2021, at 9:42 AM, Askar Safin <safinas...@mail.ru 
> > <mailto:safinas...@mail.ru>> wrote:
> > 
> > Hi. I'm writing Avro implementation in Rust for personal use. I have a 
> > question. Consider this Avro scheme:
> > 
> > {
> >  "type": "record",
> >  "name": "a.b",
> >  "fields": [
> >    {
> >      "name": "c",
> >      "type": {
> >        "type": "record",
> >        "name": "d",
> >        "fields": []
> >      }
> >    }
> >  ]
> > }
> > 
> > What is fullname of record "c"? "a.c" or "c"? I think Avro specification is 
> > vague about this and should be fixed. When I attempt to interpret Avro spec 
> > literally, I get to conclusion that the fullname is "a.c". But this 
> > contradicts to my common sense.
> > 
> > ==
> > Askar Safin
> > http://safinaskar.com <http://safinaskar.com/>
> > https://sr.ht/~safinaskar <https://sr.ht/~safinaskar>
> > https://github.com/ <https://github.com/>

Reply via email to