add: InvalidDefer error

lib/Ast/Parser/Expr.hs

@@ -92,7 +92,7 @@ parseTerm =
       parseContinue,
       parseBlock id,
       parseCast,
-      parseDefer *> parseExpr,
+      parseDefer,
       M.try parseFunction,
       M.try parseForeignFunction,
       M.try parseDeclaration,
@@ -258,10 +258,14 @@ parseCast = do
   expr <- M.between (PU.symbol "(") (PU.symbol ")") parseExpr
   return $ AT.Cast srcLoc type' expr
 
-parseDefer :: PU.Parser ()
+parseDefer :: PU.Parser AT.Expr
 parseDefer = do
   defered <- PU.symbol "defer" *> parseExpr
   S.modify $ PS.pushDefered defered
+  next <- M.optional parseExpr
+  case next of
+    Nothing -> M.customFailure $ PU.InvalidDefer defered
+    (Just e) -> return e
 
 parseParenExpr :: PU.Parser AT.Expr
 parseParenExpr = M.between (PU.symbol "(") (PU.symbol ")") parseExpr

lib/Ast/Parser/Utils.hs

@@ -14,20 +14,17 @@ type Parser = M.ParsecT ParseErrorCustom String (S.State PS.ParserState)
 
 data ParseErrorCustom
   = UnknownType String
-  | UndefinedVar String
-  | UndefinedFunction String
   | InvalidFunctionType String AT.Type
+  | InvalidDefer AT.Expr
   deriving (Show, Ord, Eq)
 
 instance M.ShowErrorComponent ParseErrorCustom where
   showErrorComponent (UnknownType n) =
     "Unknown type: type \"" ++ n ++ "\" does not exist"
-  showErrorComponent (UndefinedVar n) =
-    "Undefined Variable: variable \"" ++ n ++ "\" is not defined"
-  showErrorComponent (UndefinedFunction n) =
-    "Undefined Function: function \"" ++ n ++ "\" is not defined"
   showErrorComponent (InvalidFunctionType n t) =
     "Invalid Function Type: function \"" ++ n ++ "\" with type \"" ++ show t ++ "\" is not valid"
+  showErrorComponent (InvalidDefer e) =
+    "Invalid Defer: defer \"" ++ show e ++ "\" is not valid "
 
 -- | Skips whitespace and comments (starting with `%`). Ensures proper handling of spacing in parsers.
 sc :: Parser ()