Synopsis

"You do with Mogwai what your society has done with all of nature's gifts! You do not understand! You are not ready. Perhaps someday, you may be ready. Until then, Mogwai will be waiting."

• Mr. Wing

A graph traversal enabled Entity Component System.

This is highly experimental, I would not use this if I where you!

Code Example

Fetching rooms with walls that have windows and resolving relational dependencies:

const W = new World();
createGraphWithRoomsWallsAndWindows(W);
W.fetch().on((t: M.VertexTraverser) => t
  // rooms with windows
  .hasLabel("window").in().hasLabel("wall").in("has"))
  // subfetching starts from each vertex and applies the traverser.
  .subFetch("walls", (t: M.VertexTraverser) => t
    .out("has").hasLabel("wall"))
  .subFetch("windows", (t: M.VertexTraverser) => t
    .out("has").hasLabel("wall")
    .out("has").hasLabel("window"), "dimensions")
  .collect();

Graph traversal that creates co-author edges for vertex v1:

G = new Graph();
createGraphWithAuthorsAndAuthorship(G);
G.V(v1).as("v1")
  .let("notA", (t) => t.not())
  .let("co-authors", (t) => t.out("author-of").in("author-of") )
  .and("co-authors", "notA").as("co-authors-of-v1")
  .edgeBuilder().from("v1").to("co-authors-of-v1").label("co-author").build();

A system that is registered on a world and can be run:

const system = {
  execute: (w: World) =>  w.fetch().on(t => t.hasLabel("window")).stream()
    .each(e => console.log(e)), // do something for each window.
};
W.registerSystem("system1", system);
W.run();

Refer to the tests for actual usages and for many examples on graph traversal and graph creation.

Motivation

Entity component systems are great for typical access patterns of simulation tasks (like computer games). But we often encounter relational dependencies in our data. So Mogwai tries to implement a ECS on a graph datastructure and enables resolving and filtering relations by graph traversals.

Mogwai is heavily inspired by tinkerpop's Gremlin graph traversal language. Note however, that Mogwai is not intended to be a graph data base or tinkerpop 3.0 compliant.

Installation

Add to package.json

"dependencies": {
  "mogwai-ecs": "^0.1.5"
},

or just:

yarn add mogwai-ecs

API Reference

Tests

npm install && npm test

or

jest --watch

License

MIT.