{"action":"created","issue":{"url":"https://api.github.com/repos/Microsoft/TypeScript/issues/4651","labels_url":"https://api.github.com/repos/Microsoft/TypeScript/issues/4651/labels{/name}","comments_url":"https://api.github.com/repos/Microsoft/TypeScript/issues/4651/comments","events_url":"https://api.github.com/repos/Microsoft/TypeScript/issues/4651/events","html_url":"https://github.com/Microsoft/TypeScript/issues/4651","id":104962564,"number":4651,"title":"Question about change of type relations rules in regards to index signatures","user":{"login":"osdm","id":936705,"avatar_url":"https://avatars.githubusercontent.com/u/936705?v=3","gravatar_id":"","url":"https://api.github.com/users/osdm","html_url":"https://github.com/osdm","followers_url":"https://api.github.com/users/osdm/followers","following_url":"https://api.github.com/users/osdm/following{/other_user}","gists_url":"https://api.github.com/users/osdm/gists{/gist_id}","starred_url":"https://api.github.com/users/osdm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/osdm/subscriptions","organizations_url":"https://api.github.com/users/osdm/orgs","repos_url":"https://api.github.com/users/osdm/repos","events_url":"https://api.github.com/users/osdm/events{/privacy}","received_events_url":"https://api.github.com/users/osdm/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/Microsoft/TypeScript/labels/Question","name":"Question","color":"d4c5f9"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-09-04T20:13:03Z","updated_at":"2015-09-04T21:05:48Z","closed_at":null,"body":"From 1.6 spec, rules about subtypes/supertypes:\r\n> * M is a string index signature of type U, and U is the Any type or S has an apparent string\r\nindex signature of a type that is a subtype of U.\r\n> * M is a numeric index signature of type U, and U is the Any type or S has an apparent\r\nstring or numeric index signature of a type that is a subtype of U.\r\n\r\n\"U is the Any type or \" was added here. But similar rules for assignability weren't changed. That is strange: until 1.6 assignability rules were more relaxed than subtyping rules. What is the rationale for that? Thanks!"},"comment":{"url":"https://api.github.com/repos/Microsoft/TypeScript/issues/comments/137853240","html_url":"https://github.com/Microsoft/TypeScript/issues/4651#issuecomment-137853240","issue_url":"https://api.github.com/repos/Microsoft/TypeScript/issues/4651","id":137853240,"user":{"login":"ahejlsberg","id":4226954,"avatar_url":"https://avatars.githubusercontent.com/u/4226954?v=3","gravatar_id":"","url":"https://api.github.com/users/ahejlsberg","html_url":"https://github.com/ahejlsberg","followers_url":"https://api.github.com/users/ahejlsberg/followers","following_url":"https://api.github.com/users/ahejlsberg/following{/other_user}","gists_url":"https://api.github.com/users/ahejlsberg/gists{/gist_id}","starred_url":"https://api.github.com/users/ahejlsberg/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ahejlsberg/subscriptions","organizations_url":"https://api.github.com/users/ahejlsberg/orgs","repos_url":"https://api.github.com/users/ahejlsberg/repos","events_url":"https://api.github.com/users/ahejlsberg/events{/privacy}","received_events_url":"https://api.github.com/users/ahejlsberg/received_events","type":"User","site_admin":false},"created_at":"2015-09-04T21:05:48Z","updated_at":"2015-09-04T21:05:48Z","body":"It's an error in the spec. The new wording should also be present in the section on assignability. Thanks for pointing it out."}}