src/OptionalConfiguration.hs: import (<>) from the Semigroup class.

[mailbox-count.git] / src / OptionalConfiguration.hs

diff --git a/src/OptionalConfiguration.hs b/src/OptionalConfiguration.hs
index 0bd093b457acc174d4ed5637824c51a3eb17026d..d9627928c82b4b856e2ad0feedf66b991db22f16 100644 (file)
--- a/src/OptionalConfiguration.hs
+++ b/src/OptionalConfiguration.hs
@@ -19,8 +19,8 @@ import qualified Data.Configurator as DC (
   load,
   lookup )
 import Data.Data ( Data )
-import Data.Typeable ( Typeable )
-import Data.Monoid ( Monoid(..) )
+import Data.Monoid ( Monoid() )
+import Data.Semigroup ( Semigroup( (<>) ) )
 import Paths_mailbox_count ( getSysconfDir )
 import System.Directory ( getHomeDirectory )
 import System.FilePath ( (</>) )
@@ -36,11 +36,13 @@ data OptionalConfiguration =
   OptionalConfiguration {
     database :: Maybe String,
     detail   :: Maybe Bool,
+    detail_query :: Maybe String,
     host     :: Maybe String,
     password :: Maybe String,
     port     :: Maybe Int,
+    summary_query :: Maybe String,
     username :: Maybe String }
-  deriving (Show, Data, Typeable)
+  deriving (Show, Data)
 
 
 -- | Combine two Maybes into one, essentially mashing them
@@ -53,14 +55,30 @@ merge_maybes Nothing (Just x)  = Just x
 merge_maybes (Just _) (Just y) = Just y
 
 
--- | The Monoid instance for these lets us "combine" two
---   OptionalConfigurations. The "combine" operation that we'd like to
---   perform is, essentially, to mash them together. So if we have two
+-- | The Semigroup instance for these lets us "combine" two
+--   configurations. The "combine" operation that we'd like to perform
+--   is, essentially, to mash them together. So if we have two
 --   OptionalConfigurations, each half full, we could combine them
 --   into one big one.
 --
 --   This is used to merge command-line and config-file settings.
 --
+instance Semigroup OptionalConfiguration where
+  -- | Combine @cfg1@ and @cfg2@, giving precedence to @cfg2@.
+  cfg1 <> cfg2 =
+    OptionalConfiguration
+      (merge_maybes (database cfg1) (database cfg2))
+      (merge_maybes (detail cfg1) (detail cfg2))
+      (merge_maybes (detail_query cfg1) (detail_query cfg2))
+      (merge_maybes (host cfg1) (host cfg2))
+      (merge_maybes (password cfg1) (password cfg2))
+      (merge_maybes (port cfg1) (port cfg2))
+      (merge_maybes (summary_query cfg1) (summary_query cfg2))
+      (merge_maybes (username cfg1) (username cfg2))
+
+
+-- | The Monoid instance essentially only provides the "empty
+--   configuration."
 instance Monoid OptionalConfiguration where
   -- | An empty OptionalConfiguration.
   mempty = OptionalConfiguration
@@ -70,16 +88,9 @@ instance Monoid OptionalConfiguration where
              Nothing
              Nothing
              Nothing
-
-  -- | Combine @cfg1@ and @cfg2@, giving precedence to @cfg2@.
-  cfg1 `mappend` cfg2 =
-    OptionalConfiguration
-      (merge_maybes (database cfg1) (database cfg2))
-      (merge_maybes (detail cfg1) (detail cfg2))
-      (merge_maybes (host cfg1) (host cfg2))
-      (merge_maybes (password cfg1) (password cfg2))
-      (merge_maybes (port cfg1) (port cfg2))
-      (merge_maybes (username cfg1) (username cfg2))
+             Nothing
+             Nothing
+  mappend = (<>)
 
 
 -- | Obtain an OptionalConfiguration from mailbox-countrc in either
@@ -106,15 +117,19 @@ from_rc = do
                    DC.Optional user_config_path ]
   cfg_database <- DC.lookup cfg "database"
   cfg_detail <- DC.lookup cfg "detail"
+  cfg_detail_query <- DC.lookup cfg "detail_query"
   cfg_host <- DC.lookup cfg "host"
   cfg_password <- DC.lookup cfg "password"
   cfg_port <- DC.lookup cfg "port"
+  cfg_summary_query <- DC.lookup cfg "summary_query"
   cfg_username <- DC.lookup cfg "username"
 
   return $ OptionalConfiguration
              cfg_database
              cfg_detail
+             cfg_detail_query
              cfg_host
              cfg_password
              cfg_port
+             cfg_summary_query
              cfg_username