úÎ +ª)â     None) Obtain a  that will write logs in the df1 format to .!Generally, you will want to call - just once per application, right from your main function. For example: main ::  () main = do  $ \di -> do -- #The rest of your program goes here. -- !You can start logging right away.  di $ do  ' "Welcome to my program!" --  You can use  to separate different -- logging scopes of your program: ( "initialization" $ do -- %something something do initialization  ! "Starting web server"  "server" $ do -- And you can use  to add metadata to -- *messages logged within a particular scope. % "port" "80" $ do  A "Listening for new clients" clientAddress <- somehow get a client connection & "handler" $ do > "client-address" clientAddress $ do  3 "Connection established"  ( "Oops!") 0That program will render something like this to  (in colors!): ÿó2018-05-06T19:48:06.194579393Z NOTICE Welcome to my program! 2018-05-06T19:48:06.195041422Z /initialization NOTICE Starting web server 2018-05-06T19:48:06.195052862Z /server port=80 INFO Listening for new clients 2018-05-06T19:48:06.195059084Z /server port=80 /handler client%2daddress=192%2e168%2e0%2e25%3a32528 INFO Connection established 2018-05-06T19:48:06.195059102Z /server port=80 /handler client%2daddress=192%2e168%2e0%2e25%3a32528 exception=user%20error%20(Oops!) WARNING Exception thrown Notice that by default, all exceptions thrown using  or  are logged at their throw site with  level.(Unrelated: Notice how df1I escapes pretty much all punctuation characters. This is temporal until df1N is formalized and a more limited set of punctuation characters is reserved.)This type is the same as  -> m a..^ Within this scope, you can use the obtained ( safely, even concurrently. As soon as m a finishes, G will block until all logs have finished processing, before returning.WARNING: Even while  commit  :: m (   )3 type-checks, and you can use it to work with the @ outside the intended scope, you will have to remember to call w yourself before exiting your application. Otherwise, some log messages may be left unprocessed. If possible, use the : within this function and don't let it escape this scope.         !" !#$%&'()*+,-./0-12 !34di-1.1-OYieiT3tFWEHTvrT1ShpwDi System.IOstderrthrow df1-0.1.1-4p3RO6evVFnJe4UWSlq5ea Df1.TypesvaluekeysegmentMessageLevelSegmentKeyValuePath#di-df1-1.0.2-9sfnaFKwWa4HIfsw5S8Cwh Di.Df1.Monaddebuginfonoticewarningerrorcriticalalert emergencyattrpushDf1TMonadDf1Di.Df1Df1#di-monad-1.1-5Q7UvOwvuOlK2DqBoP7Q1NDi.MonadhoistDiTrunDiTnew$di-core-1.0.1-Iz9Ni6MOJZc7N7LyzmTKlWDi.Coreghc-prim GHC.TypesIO(exceptions-0.10.0-6QWPye6mgND8yaqYkBbggfControl.Monad.CatchthrowMbaseGHC.IO.Exception userErrorWarningGHC.Basepureflush