add constructor for cabal spec 3.0 for CabalSpecVersion type.

Author: piyush-kurur

Cabal/Distribution/CabalSpecVersion.hs

@@ -16,10 +16,11 @@ data CabalSpecVersion
     | CabalSpecV1_24
     | CabalSpecV2_0
     | CabalSpecV2_2
+    | CabalSpecV3_0
   deriving (Eq, Ord, Show, Read, Enum, Bounded, Typeable, Data, Generic)
 
 cabalSpecLatest :: CabalSpecVersion
-cabalSpecLatest = CabalSpecV2_2
+cabalSpecLatest = CabalSpecV3_0
 
 cabalSpecFeatures :: CabalSpecVersion -> Set.Set CabalFeature
 cabalSpecFeatures CabalSpecOld   = Set.empty
@@ -30,13 +31,15 @@ cabalSpecFeatures CabalSpecV2_2  = Set.fromList
     [ Elif
     , CommonStanzas
     ]
+cabalSpecFeatures CabalSpecV3_0 = cabalSpecFeatures CabalSpecV2_2
 
 cabalSpecSupports :: CabalSpecVersion -> [Int] -> Bool
 cabalSpecSupports CabalSpecOld v   = v < [1,21]
 cabalSpecSupports CabalSpecV1_22 v = v < [1,23]
 cabalSpecSupports CabalSpecV1_24 v = v < [1,25]
 cabalSpecSupports CabalSpecV2_0 v  = v < [2,1]
-cabalSpecSupports CabalSpecV2_2 _  = True
+cabalSpecSupports CabalSpecV2_2 v  = v < [2,3]
+cabalSpecSupports CabalSpecV3_0 _  = True
 
 specHasCommonStanzas :: CabalSpecVersion -> HasCommonStanzas
 specHasCommonStanzas CabalSpecV2_2 = HasCommonStanzas