For example, in perl code $obj->method(), I want to automatically replace $obj. with $obj->

I tried to use snippets to achieve this:

...
"Object->": {
  "prefix": ".",
  "body": [
    "->$0"
  ],
  "description": ". convert to ->"
}

But when inputting . and TAB key, it cannot be triggered effectively.
What’s the problem?

Please help, thank you very much.