{"action":"closed","issue":{"url":"https://api.github.com/repos/hkuplg/fcore/issues/69","labels_url":"https://api.github.com/repos/hkuplg/fcore/issues/69/labels{/name}","comments_url":"https://api.github.com/repos/hkuplg/fcore/issues/69/comments","events_url":"https://api.github.com/repos/hkuplg/fcore/issues/69/events","html_url":"https://github.com/hkuplg/fcore/issues/69","id":59607067,"number":69,"title":"Error in handling data type","user":{"login":"zonyitoo","id":1067951,"avatar_url":"https://avatars.githubusercontent.com/u/1067951?v=3","gravatar_id":"","url":"https://api.github.com/users/zonyitoo","html_url":"https://github.com/zonyitoo","followers_url":"https://api.github.com/users/zonyitoo/followers","following_url":"https://api.github.com/users/zonyitoo/following{/other_user}","gists_url":"https://api.github.com/users/zonyitoo/gists{/gist_id}","starred_url":"https://api.github.com/users/zonyitoo/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/zonyitoo/subscriptions","organizations_url":"https://api.github.com/users/zonyitoo/orgs","repos_url":"https://api.github.com/users/zonyitoo/repos","events_url":"https://api.github.com/users/zonyitoo/events{/privacy}","received_events_url":"https://api.github.com/users/zonyitoo/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-03-03T07:53:22Z","updated_at":"2015-03-03T08:23:15Z","closed_at":"2015-03-03T08:23:15Z","body":"For example\r\n\r\n```\r\ndata PolyList A = Nil\r\n                | Cons A (PolyList[A]);\r\n\r\ndata PolyString = PolyList Char;\r\n\r\nlet item = \\(inp: PolyString) ->\r\n    case inp of\r\n        Nil             ->    Nil\r\n      | Cons x xs       ->   Cons [(Char, PolyString)] (x, xs) Nil;\r\n```\r\n\r\nCompiler said\r\n\r\n```\r\nerror: type mismatch:\r\n  expected: PolyString\r\n    actual: (forall A. PolyList A)\r\n```\r\n\r\nI think it treats Nil as a `PolyList` type instead of a `PolyString`."}}