通过

A promise can serve as a proxy for another object, even a remote object. There are methods that allow you to optimistically manipulate properties or call functions. All of these interactions return promises, so they can be chained.

direct manipulation         using a promise as a proxy
--------------------------  -------------------------------
value.foo                   promise.get("foo")
value.foo = value           promise.put("foo", value)
delete value.foo            promise.del("foo")
value.foo(...args)          promise.post("foo", [args])
value.foo(...args)          promise.invoke("foo", ...args)
value(...args)              promise.fapply([args])
value(...args)              promise.fcall(...args)

If the promise is a proxy for a remote object, you can shave round-trips by using these functions instead of then. To take advantage of promises for remote objects, check out Q-Connection.

Even in the case of non-remote objects, these methods can be used as shorthand for particularly-simple fulfillment handlers. For example, you can replace

return Q.fcall(function () {
    return [{ foo: "bar" }, { foo: "baz" }];
})
.then(function (value) {
    return value[0].foo;
});

with

return Q.fcall(function () {
    return [{ foo: "bar" }, { foo: "baz" }];
})
.get(0)
.get("foo");