Sending and receiving

In addition to keeping state on the server, Path also aims at reducing the responsibility of a caller for holding on to a call context until a response is received. This sort of call frame maintenance anticipating callback execution is an essential condition of nearly all AJAX development patterns, and is typically represented as follows:

//Within some execution context, such as an autocomplete input
someXhrProxy.get("/a/path/", function(data) {
  //A callback bound to the execution context via closures
});

Some client-side libraries attempt to simplify this pattern with abstractions like Promises, but they miss the point: a call should "fire and forget", its job being solely the transmission of a request. The impact of that action, for both the server and the client, is not the caller's concern. A developer only needs to assert a desired change of state, or request some information. Path facilitates this separation of concerns, absolves the...