On Sat, Aug 6, 2011 at 5:51 AM, Niels Hoogeveen <pd_aficion...@hotmail.com>wrote:
> ....... > Every part of the database can be accessed with a traveral description. > > The standard Neo4j API only allows traversals to return Nodes given a start > Node. The Enhanced API allows traversals from any part of the graph, whether > it is a regular Vertex, an Edge or a Property (or a type thereof), to any > other part of the graph, no matter if it is a regular Vertex, an Edge or a > Property (or a type thereof). > > All that needs to be supplied are the EdgeTypes that need to be followed in > a traversal (and the regular evaluators that go with it). > > Now the big downer to this all: > > I still have to write the traversal framework, which will actually follow > the Standard Neo4j framework, but will certainly make traversals composable. > > Every Vertex is not just a Vertex, but it is also a bunch of paths. Well > not really a bunch, it is a bunch of size one, and not much of a path > either, since it only contains one path element, the Vertex itself. > > A traversal returns a bunch of paths (Iterable<Path>) and starts from a > bunch of paths (still Iterable<Path>). > > Since the output of a traversal is the same as the input of a traversal we > can now compose them. This makes it possible to write a traversal > description which states that we want to retrieve the parents of our > friends, or the neighbours of the parents of our friends, and even: the > names of the dogs of the neighbours of the parents of our friends (after > all, we can now traverse to a property). > > This can be achieved when we make traversal descriptions composable. Most > users probably don't want to manually compose traversals, they would much > rather compose traversal descriptions and let those descriptions do the > composition of the traversals. > I have to write quite complex traversal and can't do it so far. The use case quite simple, there can be several type of paths: (1) REF->GET->... (2) REF->( HAVE | IC )->... (3) IS*->REF->( HAVE | IC )->... (* - can be several IS relationships) 2 & 3 is allowed, but 1 is not. For cases 1 & 2 traversal simple to write, but as soon as adding case 3 everything crash. One of possible solution is 'state' at paths or maybe I over-engineering it =) -- Dmitriy Shabanov _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
