Parse enums from headers & generate code (#19)

src/DearImGui/Enums.hs

@@ -0,0 +1,34 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE MagicHash #-}
+{-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeFamilies #-}
+
+module DearImGui.Enums where
+
+-- base
+import GHC.Exts
+  ( proxy# )
+import GHC.TypeNats
+  ( Nat, KnownNat, natVal' )
+import Numeric.Natural
+  ( Natural )
+
+-- dear-imgui-generator
+import DearImGui.Generator
+  ( declareEnumerations )
+
+--------------------------------------------------------------------------------
+
+class KnownNat ( Count a ) => FiniteEnum a where
+  type Count a :: Nat
+  count :: Natural
+  count = natVal' @( Count a ) proxy#
+
+declareEnumerations ''FiniteEnum ''Count