Crate cayley

Google Cayley Database Driver

Hosted at Github.

Jump to: Graph | Vertex | Morphism.

Connection

To connect to a graph, start Cayley itself:

$ ./cayley http --dbpath=<your-database>

Then, bind driver to your host this way:

use cayley::{Graph, DefaultVersion};
let graph = match Graph::new("localhost", 64210, DefaultVersion) {
   Err(error) => fail!(error),
   Ok(graph) => graph
};

For the moment, this code performs no connection at all, when you only create a Graph. On the other hand, the connection is established for every query. So this error, if happened, is not telling that connection was failed here, it just tells about malformed URL. But things may change, and even when they'll do, you still have a chance to pattern-match the error, if you need.

Query

Query pattern looks like this:

use cayley::{Graph, DefaultVersion};
use cayley::GraphNodes;
use cayley::path::{Vertex, Query}; // Query trait import is required
use cayley::selector::AnyNode;

let graph = Graph::new("localhost", 64210, DefaultVersion).unwrap();
match graph.find(Vertex::start(AnyNode).All()) {
   Ok(GraphNodes(nodes)) => assert!(nodes.len() > 0),
   Err(error) => fail!(error.to_string()),
};

So in general it looks like graph.find(<Query>).

GraphNodes is a wrapper for Vec<GraphNode>. GraphNode is a wrapper for HashMap<String, String>

Morphism used this way:

#![allow(unused_result)]
use cayley::{Graph, DefaultVersion};
use cayley::path::Vertex as V;
use cayley::path::Morphism as M;
use cayley::path::{Path, Query}; // both traits imports are required
use cayley::selector::{Predicate, Node};

let graph = Graph::new("localhost", 64210, DefaultVersion).unwrap();
let mut follows_m = M::start("foo");
        follows_m.OutP(Predicate("follows"));
graph.save(&mut follows_m).unwrap();
graph.find(V::start(Node("C"))
             .Follow(&follows_m)
             .Has(Predicate("status"), Node("cool_person"))
             .All()).unwrap();

API

Gremlin API is implemented through these entry points:

• Graph provides .find(<Query>) and .save(<Morphism>);
• Vertex provides:
  • Path implemetation with .Out(...), .In(...), .Has(...), .Or(...), .Follow(...), ...
  • Query implemetation with .All(), .GetLimit(...), ...
• Morphism provides:
  • Path implemetation with .Out(...), .In(...), .Has(...), .Or(...), .Follow(...), ...

Follow the links above for a complete lists of methods and to get more information about every mentioned structure.

Reexports

pub use graph::{Graph, GraphNodes, GraphNode};

pub use graph::{V1, DefaultVersion};

Modules

errors
graph
path
selector