Wrong patch when substituting an object for an array?

```
> jsonpatch.compare({a: {}}, {a: [1]});
[{op: "add", path: "/a/0", value: 1}]
```

Shouldn't be the empty object replaced with the array? the value is no longer an object.

```
[{op: "replace", path: "/a", value: [1]}]
```
