WIP typecheck and other stuff

1 files changed, 4 insertions, 1 deletions

diff --git a/src/HSVIS/Diagnostic.hs b/src/HSVIS/Diagnostic.hs
index 75a677f..322f9eb 100644
--- a/src/HSVIS/Diagnostic.hs
+++ b/src/HSVIS/Diagnostic.hs
@@ -7,12 +7,15 @@ data Pos = Pos
   { posLine :: Int  -- ^ zero-based
   , posCol :: Int   -- ^ zero-based
   }
-  deriving (Show)
+  deriving (Show, Eq, Ord)
 
 -- | Inclusive-exclusive range of positions in a file.
 data Range = Range Pos Pos
   deriving (Show)
 
+instance Semigroup Range where
+  Range a b <> Range c d = Range (min a c) (max b d)
+
 data Diagnostic = Diagnostic
   { dFile :: FilePath      -- ^ The file for which the diagnostic was raised
   , dRange :: Range        -- ^ Where in the file