Modify Semigroup behavior to avoid discarding (closes chrisdone-archi…

…ve#31)

CHANGELOG.md

@@ -0,0 +1,15 @@
+Changes to the `ini` package
+=====
+
+v0.5
+-----
+
+The behavior of `(<>)` and `mappend` for the `Ini` type has changed.
+
+  * `<>` previously discarded all `iniGlobals`. Now it concatenates
+    the globals from the two `Ini` values.
+
+  * When two `Ini` values contained `iniSections` with the same name,
+    `<>` previously returned the section from the left value and
+    discarded the section of the same name from the right value.
+    Now it concatenates the sections of the same name.

ini.cabal

@@ -1,5 +1,5 @@
 name:                ini
-version:             0.4.2
+version:             0.5
 synopsis:            Quick and easy configuration files in the INI format.
 description:         Quick and easy configuration files in the INI format.
 license:             BSD3
@@ -12,6 +12,7 @@ copyright:           2013 Chris Done
 category:            Data, Configuration
 build-type:          Simple
 cabal-version:       >=1.8
+extra-source-files:  CHANGELOG.md
 
 library
   hs-source-dirs:    src/

src/Data/Ini.hs

@@ -89,13 +89,16 @@ data Ini =
     }
   deriving (Show, Eq)
 
+-- | '<>' concatenates the lists of entries within each section (since @ini-0.5@)
 instance Semigroup Ini where
   (<>) = mappend
 
 instance Monoid Ini where
   mempty = Ini {iniGlobals = mempty, iniSections = mempty}
   mappend x y =
-    Ini {iniGlobals = mempty, iniSections = iniSections x <> iniSections y}
+    Ini { iniGlobals = iniGlobals x ++ iniGlobals y
+        , iniSections = M.unionWith (++) (iniSections x) (iniSections y)
+        }
 
 {-# DEPRECATED #-}
 unIni :: Ini -> HashMap Text (HashMap Text Text)