Following up on this thread, I've created a few tickets around this functionality. I think this can be tackled in 3 parts
1. Add a MAP_PUT function - https://issues.apache.org/jira/browse/METRON-2071 2. Add syntactic sugar for map get/put to Stellar and Stellar shell - https://issues.apache.org/jira/browse/METRON-2072 3. Create a use case that enables an in-memory enrichment loading via serialized maps from the flatfile summarizer - https://issues.apache.org/jira/browse/METRON-2073 I already started on #1, and aside from some documentation updates and a few more unit/integration tests, it's basically done. #3 might already handle caching and the ability to update enrichments with OBJECT_GET, but I haven't looked that deeply into it yet. There will also probably be some use for a MAP_MERGE, though as I'm thinking on the fly about this, we may be able to massage the REDUCE function to this purpose - https://github.com/apache/metron/tree/master/metron-stellar/stellar-common#reduce . Best, Mike On Fri, Apr 5, 2019 at 2:04 PM Michael Miklavcic < michael.miklav...@gmail.com> wrote: > Hi all, > > We have a number of data structures and functions available via Stellar > for manipulating those structures. For example, we provide the following > functions for initializing and working with Bloom filters: > [Stellar]>>> ?BLOOM_ > ?BLOOM_ADD ?BLOOM_EXISTS ?BLOOM_INIT ?BLOOM_MERGE > > For Maps, we have some functions for dealing with existing maps, e.g > MAP_GET, MAP_EXISTS. We even have a MapReduce type of function, MAP. And > from an initialization perspective, you can create a map in Stellar with > what amounts to as an empty JSON object, e.g. mymap:={}. You can also turn > JSON into a proper map using TO_JSON_MAP. > > I don't, however, see a way to add to map object contents, e.g. PUT. So > the first question I have is whether this would functionality (assuming I > haven't missed something obvious that enables this in the first place) be > valuable to anyone, or if it's even something we should enable to begin > with. A vote against this option could be the potential for users > unwittingly loading up a ton of data and encountering OOM errors. This > would be bad for running topologies. The second question is whether this > should be a language feature or a specialized set of functions, e.g. > MAP_INIT,MAP_PUT, MAP_REMOVE > vs > mymap:={} > mymap['mike']:='miklavcic' > mymap:=FILTER(mymap , (x) -> x != 'mike') > > *Note*, from the above, the only thing we appear to be missing is the > ability to add to an existing map. Initializing and removing elements can > be handled by existing functionality. > > Best, > Mike > >
