2 files changed, 44 insertions, 1 deletions
diff --git a/src/Language/Fiddle/Ast/Internal/MetaTypes.hs b/src/Language/Fiddle/Ast/Internal/MetaTypes.hs
index 2be212e..139637d 100644
--- a/src/Language/Fiddle/Ast/Internal/MetaTypes.hs
+++ b/src/Language/Fiddle/Ast/Internal/MetaTypes.hs
@@ -16,6 +16,14 @@ module Language.Fiddle.Ast.Internal.MetaTypes
     Variant (..),
     foldVariant,
     toEither,
+    getLeft,
+    getRight,
+    progress,
+    progressBack,
+    progressM,
+    progressBackM,
+    changeLeft,
+    changeRight,
   )
 where
 
@@ -223,9 +231,33 @@ toEither :: Variant b t f -> Either t f
 toEither (LeftV l) = Left l
 toEither (RightV l) = Right l
 
+getLeft :: Variant True l r -> l
+getLeft (LeftV l) = l
+
+getRight :: Variant False l r -> r
+getRight (RightV r) = r
+
 foldVariant :: (t -> r) -> (f -> r) -> Variant b t f -> r
 foldVariant fl fr = either fl fr . toEither
 
+changeLeft :: Variant False l r -> Variant False l' r
+changeLeft (RightV r) = RightV r
+
+changeRight :: Variant True l r -> Variant True l r'
+changeRight (LeftV r) = LeftV r
+
+progressM :: (Functor m) => (l -> m r) -> Variant True l r -> m (Variant False l' r)
+progressM fn (LeftV l) = RightV <$> fn l
+
+progress :: (l -> r) -> Variant True l r -> Variant False l' r
+progress fn (LeftV l) = RightV (fn l)
+
+progressBack :: (r -> l) -> Variant False l r -> Variant True l r'
+progressBack fn (RightV r) = LeftV (fn r)
+
+progressBackM :: (Functor m) => (r -> m l) -> Variant False l r -> m (Variant True l r')
+progressBackM fn (RightV r) = LeftV <$> fn r
+
 instance Functor (Variant b t) where
   fmap _ (LeftV x) = LeftV x
   fmap f (RightV x) = RightV (f x)
diff --git a/src/Language/Fiddle/Ast/Internal/SyntaxTree.hs b/src/Language/Fiddle/Ast/Internal/SyntaxTree.hs
index 0d0bc32..b597a25 100644
--- a/src/Language/Fiddle/Ast/Internal/SyntaxTree.hs
+++ b/src/Language/Fiddle/Ast/Internal/SyntaxTree.hs
@@ -18,6 +18,7 @@ module Language.Fiddle.Ast.Internal.SyntaxTree
     FieldSpan (..),
     QRegMetadata (..),
     QBitsMetadata (..),
+    RegSz(..),
     -- Witness Types
     Witness (..),
     -- AST Types
@@ -50,6 +51,7 @@ module Language.Fiddle.Ast.Internal.SyntaxTree
     EnumConstantDecl (..),
     PackageBody (..),
     -- Helper Functions
+    regSzToBits,
     mapDirected,
     mapDirectedM,
     asDirected,
@@ -105,6 +107,15 @@ deriving instance
   (FromJSON (When s (FieldSpan Bytes))) =>
   FromJSON (QRegMetadata s)
 
+data RegSz = RegSz8 | RegSz16 | RegSz32  | RegSz64
+  deriving (Eq, Ord, Show, Enum, Generic, ToJSON, FromJSON)
+
+regSzToBits :: RegSz -> N Bits
+regSzToBits RegSz8 = 8
+regSzToBits RegSz16 = 16
+regSzToBits RegSz32 = 32
+regSzToBits RegSz64 = 64
+
 data QBitsMetadata (checkStage :: Bool) where
   QBitsMetadata ::
     { bitsSpan :: When checkStage (FieldSpan Bits),
@@ -520,7 +531,7 @@ data ObjTypeDecl stage f a where
       -- doesn't exist.
       regIdent :: Guaranteed (stage .>= Qualified) (Identifier f a),
       -- | Size of the register.
-      regSize :: Expression Bits stage f a,
+      regSize :: Variant (stage .>= Qualified) RegSz (Expression Bits stage f a),
       -- | Optional register body.
       regBody :: Maybe (RegisterBody stage f a),
       -- | Annotation for the register declaration.