Panic module.

src/Panic.hs

@@ -0,0 +1,17 @@
+module Panic (
+  FatalError(..),
+  panic,
+) where
+
+import Base (Show)
+import Data.Text(Text)
+import Control.Exception as X
+
+-- | Uncatchable exceptions thrown and never caught.
+data FatalError = FatalError { msg :: Text }
+  deriving (Show)
+
+instance Exception FatalError
+
+panic :: Text -> a
+panic a = throw (FatalError a)