Add types for name analysis

lib/Language/Elna/Location.hs

@@ -0,0 +1,58 @@
+module Language.Elna.Location
+    ( Identifier(..)
+    , Location(..)
+    , Node(..)
+    , showArrayType
+    ) where
+
+import Data.Hashable (Hashable(..))
+import Data.String (IsString(..))
+import Data.Text (Text)
+import qualified Data.Text as Text
+import Data.Word (Word32)
+
+data Location = Location
+    { line :: Word32
+    , column :: Word32
+    } deriving (Eq, Show)
+
+instance Semigroup Location
+  where
+    (Location thisLine thisColumn) <> (Location thatLine thatColumn) = Location
+        { line = thisLine + thatLine
+        , column = thisColumn + thatColumn
+        }
+
+instance Monoid Location
+  where
+   mempty = Location{ line = 1, column = 1 }
+
+data Node a = Node a Location
+    deriving (Eq, Show)
+
+instance Functor Node
+  where
+    fmap f (Node node location) = Node (f node) location
+
+newtype Identifier = Identifier { unIdentifier :: Text }
+    deriving Eq
+
+instance Show Identifier
+  where
+    show (Identifier identifier) = Text.unpack identifier
+
+instance IsString Identifier
+  where
+    fromString = Identifier . Text.pack
+
+instance Ord Identifier
+  where
+    compare (Identifier lhs) (Identifier rhs) = compare lhs rhs
+
+instance Hashable Identifier
+  where
+    hashWithSalt salt (Identifier identifier) = hashWithSalt salt identifier
+
+showArrayType :: Show a => Word32 -> a -> String
+showArrayType elementCount typeName = concat
+    ["array[", show elementCount, "] of ", show typeName]