Initial thought: if the ASCII art syntax is Cypher-like, why not make it openCypher proper? I.e. keep match() as it is, but generalize the cypher() step out of Neo4jGraph, with native Neo4j evaluation of Cypher as an optimization.
Josh On Thu, Feb 4, 2021 at 2:17 PM David Bechberger <[email protected]> wrote: > Over the years of working with Gremlin I have foudn the match() step is > difficult to create traversals with and even more difficult to make it work > efficently. While the imperative style of programming in Gremlin provides > a powerful path finding mechanism it really lacks an easy way to perform > pattern matching queries. It would be great if we could simplify the > match() step to enable users to easily generate these pattern matching > traversals. > > To accomplish this I was wondering what adding support for a subset of > motif/ascii art patterns to the match step might look like. These types of > patterns are very easy for people to understand and I think the ability to > combine these pattern matching syntax with the powerful path finding and > formatting features of Gremlin would make a powerful combination. > > To accomplish this I am suggesting supporting a subset of potential > patterns. The two most common examples of this sort of pattern out there > are the openCypher type style and the style used by GraphX. I have > provided a few examples below of what this syntax might look like: > > e.g. openCypher style > > Find me everything within one hop > g.V().match("()-[]->()") > > Find me everything within one hop of a Person vertex > g.V().match("(p:Person)-[]->()") > > Find me all Companies within one hop of a Person vertex > g.V().match("(p:Person)-[]->(c:Company)") > > Find me all Companies within one hop of a Person vertex with an Employed_at > edge > g.V().match("(p:Person)-[e:employed_at]->(c:Company)") > > > The other option would be to take more of a hybrid approach and use only > the basic art/motifs like GraphX and apply the additional filtering in a > hybrid type of mode like this: > > Find me all Companies within one hop of a Person vertex with an Employed_at > edge > g.V().match("(p)-[e]->(c)", > __.as('p').hasLabel('Person'), > __.as('e').hasLabel('employed_at'), > __.as('c').hasLabel('Company'), > ) > > This also has the potential to enable some significantly more complex > patterns like "Find me all Companies within one hop of a Person vertex with > an Employed_at edge who also worked at Foo" > g.V().match("(p)-[e]->(c)", > __.as('p').hasLabel('Person').out('employed_at').has('Company', 'name', > 'Foo'), > __.as('e').hasLabel('employed_at'), > __.as('c').hasLabel('Company'), > ) > > Thoughts? > > Dave >
