On 2016-07-15 14:44 (+0100), Robert Dale <robd...@gmail.com> wrote: > It looks to me like a self-inflicted problem because the things that > are typed are already native to json so it's redundant. And to go a > step further, I wouldn't consider the types to be 'correct' because > everything that is a HashMap is really a Vertex, Edge, or Property. > > On Thu, Jul 14, 2016 at 10:03 AM, gallardo.kev...@gmail.com > <gallardo.kev...@gmail.com> wrote: > > > > > > On 2016-07-13 13:17 (+0100), Robert Dale <robd...@gmail.com> wrote: > >> Marko, I agree that empty object properties should not be represented. > >> I think if you saw that in an example then it was probably for > >> demonstration purposes. > >> > >> Kevin, can you expand on this comment: > >> > >> > the format you suggest would lead to the same inconsistencies as in > >> > GraphSON 1.0. > >> > Since the type is at the same level than the data itself, whether the > >> > container is an Array or an Object > >> > https://github.com/apache/tinkerpop/pull/351#issuecomment-231351653 > >> > >> What exactly are the inconsistencies? What is the problem in > >> determining an array or object? > >> This is a natural JSON array (or list): [] > >> This is a natural JSON object: {} > >> > >> Type at the object level is a common pattern and supported feature of > >> Jackson. Also, GeoJSON would be a natural fit as it also stores > >> 'type' at the object level. Titan supports GeoJSON currently. I > >> wonder if it would make sense to promote geometry to gremlin. > >> > > > > I wasn't probably clear enough, in my first email exposing my motivation to > > improve GraphSON 1.0, one of the things I noticed was that according to the > > enclosing element (either an Array or a Map), a type will either be > > described as (respectively) an element of the Array, or a key/value pair in > > a Map, you can see that in the "embedded types" example of the Tinkerpop > > docs : > > http://tinkerpop.apache.org/docs/current/reference/#graphson-reader-writer . > > > > There you can see that the type "java.util.ArrayList" is a simple element > > of the enclosing array, but the "java.util.HashMap" type is a field of the > > enclosing Map as {"@class" : "java.util.HashMap", ...}. This does not seem > > consistent to me and even though I know that Jackson handles it well, it > > seems that we'd better provide a consistent enclosing format that we know > > is fixed whatever the enclosed data is, to make the automatic type > > detection for other parsers in other libraries/languages easier. Does that > > make sense ? > > > >> We should probably start documenting a table of supported types. (If > >> there is one, please provide link) > >> > >> I wonder if it even makes sense to type numbers according to their > >> memory model. As objects, Byte, Short, and Integer occupy the same > >> space. Long isn't much more. So in Java we're not saving much space. > >> Jackson will attempt to parse in order: int, long, BigInt, BigDecimal. > >> The JSON JSR uses only BigDecimal. Some non-jvm languages don't even > >> have this concept. Does anything in gremlin actually require this? > >> I'm thinking that this is only going to be relevant at the domain > >> model level. This way json native numbers can be used and not need > >> typing. > >> > >> Additionally, I think that all things that will be typed should always > >> be typed. For the use cases of injesting a saved graph from a file, it > >> can probably be assumed that the top-level objects are vertices since > >> the graph is vertex-centric and everything else follows naturally. > >> I'm not entirely sure what is required for submitting traversals to > >> gremlin server from GLV. However, if this is used for the results > >> from gremlin server then the results could start with any one of path, > >> vertex, edge, property, vertex property, etc. So you'll need that type > >> data there. > >> > >> -- > >> Robert Dale > >> > >> On Tue, Jul 12, 2016 at 8:35 AM, Marko Rodriguez <okramma...@gmail.com> > >> wrote: > >> > Hi, > >> > > >> > Iâm not following this PR too closely so what I might be saying is a > >> > already known/argued against/etc. > >> > > >> > 1. I think we should go with Robert Daleâs proposal of int32, > >> > int64, Vertex, uuid, etc. instead of Java class names. > >> > 2. In Java we then have a Map<String,Class> for typecasting > >> > accordingly. > >> > 3. This would make GraphSON 2.0 perfect for Bytecode > >> > serialization in TINKERPOP-1278. > >> > 4. I think that if a Vertex, Edge, etc. doesnât have > >> > properties, outV, etc. then donât even have those fields in the > >> > representation. > >> > 5. Most of the serialization back and forth will be ReferenceXXX > >> > elements and thus, donât create more Maps/lists for no reason. â > >> > less chars. > >> > > >> > For me, my interests with this work is all about a language agnostic way > >> > of sending Gremlin traversal bytecode between different languages. This > >> > work is exactly what I am looking for. > >> > > >> > Thanks, > >> > Marko. > >> > > >> > http://markorodriguez.com > >> > > >> > > >> > > >> >> On Jul 9, 2016, at 9:48 AM, Stephen Mallette <spmalle...@gmail.com> > >> >> wrote: > >> >> > >> >> With all the work on GLVs and the recent work on GraphSON 2.0, I think > >> >> it's > >> >> important that we have a solid, efficient, programming language neutral, > >> >> lossless serialization format. Right now that format is GraphSON and it > >> >> works for that purpose (ever more so with 2.0). Given some discussion > >> >> on > >> >> the GraphSON 2.0 PR driven a bit by Robert Dale: > >> >> > >> >> https://github.com/apache/tinkerpop/pull/351#issuecomment-231157389 > >> >> > >> >> I wonder if we shouldn't consider another IO format that has Gremlin > >> >> Server/GLVs in mind. At this point I'm not suggesting anything specific > >> >> - > >> >> I'm just hanging the idea out for further discussion and brain storming. > >> >> Thoughts? > >> > > >> > >> > >> > >> -- > >> Robert Dale > > > > -- > Robert Dale > Correct, these types weren't relevant... I only wanted to show you the > format... However, I don't manage to understand the structure behind the format you suggest, and I don't manage to establish a clear explicit representation in my mind, regarding the example you provided in the TP-1274 PR. Could you please give an example of how you would imagine the serialized JSON of : - an example list of typed values, like List<UUID> - an example list of typed and untyped values, like a list with UUIDs and booleans - an example map of typed and untyped values
How would you define that format in a general way ? Like what I did when saying "- untyped : value - typed : {"@type", "typeName", "value" : value}" Just trying your point better. Also what are the downsides you see with the format suggested above ?