{"action":"created","issue":{"url":"https://api.github.com/repos/ndmitchell/hlint/issues/238","repository_url":"https://api.github.com/repos/ndmitchell/hlint","labels_url":"https://api.github.com/repos/ndmitchell/hlint/issues/238/labels{/name}","comments_url":"https://api.github.com/repos/ndmitchell/hlint/issues/238/comments","events_url":"https://api.github.com/repos/ndmitchell/hlint/issues/238/events","html_url":"https://github.com/ndmitchell/hlint/issues/238","id":154981930,"number":238,"title":"Incorrect RegularPatterns extension suggestion.","user":{"login":"mrakgr","id":6266635,"avatar_url":"https://avatars.githubusercontent.com/u/6266635?v=3","gravatar_id":"","url":"https://api.github.com/users/mrakgr","html_url":"https://github.com/mrakgr","followers_url":"https://api.github.com/users/mrakgr/followers","following_url":"https://api.github.com/users/mrakgr/following{/other_user}","gists_url":"https://api.github.com/users/mrakgr/gists{/gist_id}","starred_url":"https://api.github.com/users/mrakgr/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mrakgr/subscriptions","organizations_url":"https://api.github.com/users/mrakgr/orgs","repos_url":"https://api.github.com/users/mrakgr/repos","events_url":"https://api.github.com/users/mrakgr/events{/privacy}","received_events_url":"https://api.github.com/users/mrakgr/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-05-16T08:17:05Z","updated_at":"2016-05-16T09:09:23Z","closed_at":null,"body":"More details in this [SO](http://stackoverflow.com/questions/37224366/how-to-resolve-an-unsupported-extension-regularpatterns-error) question and [here](https://github.com/atom-haskell/ide-haskell/issues/160). It seems that the `RegularPatterns` language extension got removed at some point, but `hlint` was not updated to reflect that. The code that triggers the error is in the second link."},"comment":{"url":"https://api.github.com/repos/ndmitchell/hlint/issues/comments/219381870","html_url":"https://github.com/ndmitchell/hlint/issues/238#issuecomment-219381870","issue_url":"https://api.github.com/repos/ndmitchell/hlint/issues/238","id":219381870,"user":{"login":"lierdakil","id":7275622,"avatar_url":"https://avatars.githubusercontent.com/u/7275622?v=3","gravatar_id":"","url":"https://api.github.com/users/lierdakil","html_url":"https://github.com/lierdakil","followers_url":"https://api.github.com/users/lierdakil/followers","following_url":"https://api.github.com/users/lierdakil/following{/other_user}","gists_url":"https://api.github.com/users/lierdakil/gists{/gist_id}","starred_url":"https://api.github.com/users/lierdakil/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/lierdakil/subscriptions","organizations_url":"https://api.github.com/users/lierdakil/orgs","repos_url":"https://api.github.com/users/lierdakil/repos","events_url":"https://api.github.com/users/lierdakil/events{/privacy}","received_events_url":"https://api.github.com/users/lierdakil/received_events","type":"User","site_admin":false},"created_at":"2016-05-16T09:09:23Z","updated_at":"2016-05-16T09:09:23Z","body":"A bit more information.\r\n\r\n```\r\nError: Parse error: RegularPatterns language extension is not enabled. Please add {-# LANGUAGE RegularPatterns #-} pragma at the top of your module.\r\n```\r\n\r\nmessage is generated by haskell-src-exts. It bears mentioning that there is no (and never was) such a language extension in GHC.\r\n\r\nIt was, at one point, provided by third-party HaRP preprocessor, but I don't think many people actually use it (not sure if it's still usable either)\r\n\r\nIn any case, this error message is *highly* misleading.\r\n\r\nP.S. BTW, even with pragma added, hlint fails to parse even basic examples from https://web.archive.org/web/20090226145238/http://www.cs.chalmers.se/~d00nibro/harp/examples.html -- not sure if it's HSE's fault or not."}}