Level07 wording changes.

level07/src/FirstApp/AppM.hs

@@ -91,9 +91,6 @@ data Env = Env
 --
 -- But ExceptT has an `m` type variable, so what do we put there?
 --
--- The answer is to put the IO that we replaced as the base monad for ExceptT.
---
--- This gives us the final AppM looking like:
 newtype AppM a = AppM
   { unAppM :: _ }
   deriving ( Functor
@@ -106,17 +103,17 @@ newtype AppM a = AppM
            , MonadError Error
            )
 
+-- Now that we've two transfomers in out 'stack', we have to 'run' them in order
+-- to effect the computations and produce our result in our base monad. When
+-- you're running monad transformers you have to unpack them in order. Since our outer
+-- transformer is a ReaderT, we have to run that first. Followed by running
+-- the ExceptT to retrieve our `IO (Either Error a)`.
 runAppM
   :: Env
   -> AppM a
   -> IO (Either Error a)
 runAppM env appM =
   error "runAppM not reimplemented"
-  -- Now that we've two transfomers in out 'stack', we have to 'run' them in order
-  -- to effect the computations and produce our result in our base monad. When
-  -- you're running monad transformers you have to unpack them in order. Since our outer
-  -- transformer is a ReaderT, we have to run that first. Followed by running
-  -- the ExceptT to retrieve our `IO (Either Error a)`.
 
 -- This is a helper function that will `lift` an Either value into our new AppM
 -- by applying `throwError` to the Left value, and using `pure` to lift the

level07/src/FirstApp/Conf.hs

@@ -147,6 +147,11 @@ parseJSONConfigFile fp = do
       ( fromObj "dbFilePath" id cObj )
 
     -- Parse out the keys from the object, maybe...
+    -- >>> fromObj "foo" id (encode "{\"foo\":\"Susan\"}")
+    -- Last (Just "Susan")
+    -- >>> fromObj "foo" id (encode "{\"bar\":33}")
+    -- Last Nothing
+    --
     fromObj
       :: FromJSON a
       => Text

level07/src/FirstApp/Types.hs

@@ -47,7 +47,8 @@ data Comment = Comment
   , commentText  :: CommentText
   , commentTime  :: UTCTime
   }
-  -- Generic has been added to our deriving list.
+  -- Generic has been added to our deriving list. This will require the
+  -- DeriveGeneric pragma to be added to the top of the file
   deriving ( Show, Generic )
 
 instance ToJSON Comment where