{"action":"created","issue":{"url":"https://api.github.com/repos/ambv/typehinting/issues/157","labels_url":"https://api.github.com/repos/ambv/typehinting/issues/157/labels{/name}","comments_url":"https://api.github.com/repos/ambv/typehinting/issues/157/comments","events_url":"https://api.github.com/repos/ambv/typehinting/issues/157/events","html_url":"https://github.com/ambv/typehinting/issues/157","id":107961051,"number":157,"title":"How to annotate empty containers?","user":{"login":"matthiaskramm","id":306087,"avatar_url":"https://avatars.githubusercontent.com/u/306087?v=3","gravatar_id":"","url":"https://api.github.com/users/matthiaskramm","html_url":"https://github.com/matthiaskramm","followers_url":"https://api.github.com/users/matthiaskramm/followers","following_url":"https://api.github.com/users/matthiaskramm/following{/other_user}","gists_url":"https://api.github.com/users/matthiaskramm/gists{/gist_id}","starred_url":"https://api.github.com/users/matthiaskramm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/matthiaskramm/subscriptions","organizations_url":"https://api.github.com/users/matthiaskramm/orgs","repos_url":"https://api.github.com/users/matthiaskramm/repos","events_url":"https://api.github.com/users/matthiaskramm/events{/privacy}","received_events_url":"https://api.github.com/users/matthiaskramm/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-09-23T16:50:27Z","updated_at":"2015-09-23T18:33:01Z","closed_at":null,"body":"Suppose I have a function that returns an empty list:\r\n\r\n```\r\ndef make_list():\r\n  return []\r\n```\r\n\r\nHow to best annotate the return type?\r\n\r\n```\r\ndef make_list() -> List: ...  # presumably equivalent to List[Any], hence too general\r\ndef make_list() -> List[]: ...  # invalid syntax\r\n```"},"comment":{"url":"https://api.github.com/repos/ambv/typehinting/issues/comments/142690600","html_url":"https://github.com/ambv/typehinting/issues/157#issuecomment-142690600","issue_url":"https://api.github.com/repos/ambv/typehinting/issues/157","id":142690600,"user":{"login":"gvanrossum","id":2894642,"avatar_url":"https://avatars.githubusercontent.com/u/2894642?v=3","gravatar_id":"","url":"https://api.github.com/users/gvanrossum","html_url":"https://github.com/gvanrossum","followers_url":"https://api.github.com/users/gvanrossum/followers","following_url":"https://api.github.com/users/gvanrossum/following{/other_user}","gists_url":"https://api.github.com/users/gvanrossum/gists{/gist_id}","starred_url":"https://api.github.com/users/gvanrossum/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/gvanrossum/subscriptions","organizations_url":"https://api.github.com/users/gvanrossum/orgs","repos_url":"https://api.github.com/users/gvanrossum/repos","events_url":"https://api.github.com/users/gvanrossum/events{/privacy}","received_events_url":"https://api.github.com/users/gvanrossum/received_events","type":"User","site_admin":false},"created_at":"2015-09-23T18:33:01Z","updated_at":"2015-09-23T18:33:01Z","body":"Still looks very theoretical to me. Why would anyone call chain(*a) knowing that a is an empty list? It also smells like Haskell-style pattern matching to me, which is just not a direction I want Python to take."}}