I'm building a web app using scotty and persistent and having some troubles compiling. This is my code:
runDb :: SqlPersist (ResourceT IO) a -> IO a
runDb query = runResourceT . withSqliteConn "dev.app.sqlite3" . runSqlConn $ query
readMessage :: KeyBackend (PersistEntityBackend Post) Post -> IO (Maybe Post)
readMessage postID = runDb $ get postID
And I get this error message:
Message.hs:30:30:
No instance for (Control.Monad.Logger.MonadLogger IO)
arising from a use of `get'
Possible fix:
add an instance declaration for
(Control.Monad.Logger.MonadLogger IO)
In the second argument of `($)', namely `get postID'
In the expression: runDb $ get postID
In an equation for `readMessage':
readMessage postID = runDb $ get postID
I found this question, but the accepted answer is use an old version of monad-logger which would also force me to use old versions of many other packages, scotty and persistent included, and I don't want to do that. The other answer recommends using runNoLoggingT, which I was unable to get working. I couldn't figure out where to put it to get it to typecheck.