all: added parenthesized expressions

src/BC/Eval.hs

@@ -47,6 +47,7 @@ eval state [BSym x] =
     case M.lookup x state of
       Just val -> (val, state)
       Nothing  -> (BErr (x ++ " is undefined"), state)
+eval state [BBraced vals] = eval state vals
 eval state [BCall (BSym name) args] =
     case M.lookup name state of
       Just val@BFun{} -> funCall state val args
@@ -60,6 +61,9 @@ treeEval :: State -> [Value] -> [Value] -> [Value] -> Value
 treeEval _ [] [] (num:_) = num
 treeEval state [] ops nums = handleOp state [] ops nums
 treeEval state (x@(BNum _):xy) ops nums = treeEval state xy ops (x:nums)
+treeEval state (BBraced x:xy) ops nums =
+    let (res, nstate) = eval state x
+    in treeEval nstate (res:xy) ops nums
 treeEval state (BBool x:xy) ops nums =
     treeEval state xy ops ((BNum $ BInt $ if x then 1 else 0):nums)
 treeEval state expr@(x@(BSym sym):xy) ops@(BSym op:_) nums =

src/BC/Parse.hs

@@ -131,6 +131,14 @@ fun = do
     return $ BFun name args body
 
 
+braces :: P.Parser Value
+braces = do
+       _ <- P.string "("
+       parsed <- outerparser
+       _ <- P.string ")"
+       return $ BBraced parsed
+
+
 call :: P.Parser Value
 call = do
     name <- symbol
@@ -149,6 +157,7 @@ expr = P.try bool
  P.<|> P.try while
  P.<|> P.try parseIf
  P.<|> P.try fun
+ P.<|> P.try braces
  P.<|> P.try call
  P.<|> P.try number
  P.<|> symbol

src/BC/Types.hs

@@ -11,6 +11,7 @@ data Value = BNum Number
            | BDef Value [Value]
            | BFun String [String] [[Value]]
            | BCall Value [[Value]]
+           | BBraced [Value]
            | BErr String
 instance Show Value where
   show (BBool b) = if b then "true" else "false"