Fix multiple line of expression

MINOR

lvtc/app/Main.hs

@@ -7,11 +7,10 @@
 
 module Main (main) where
 
-import Lib
 import Expression
 import Parser
 
 main :: IO ()
--- main = print $ runParser (parseExpresion) "fn main () -> Int \n{\n    <- 0;\n};\n"
+main = print $ runParser (parseExpresion) "fn main () -> Int \n{\n    <- 0;\n};\n"
 -- main = print $ runParser (parseExpresion) "alias abc def;\n"
-main = print $ runParser (parseExpresion) "// this is a comment\n"
+-- main = print $ runParser (parseExpresion) "// this is a comment\n"

lvtc/src/Expression.hs

@@ -28,8 +28,29 @@ instance Eq Expression where
     (==) (Comment str1) (Comment str2) = str1 == str2
     (==) _ _ = False
 
+countBracketsForFunction :: Int -> String -> Int
+countBracketsForFunction _ [] = 0
+countBracketsForFunction 1 ['\n', '}', ';', '\n'] = 0
+countBracketsForFunction n ['\n', '}', ';', '\n'] = n
+countBracketsForFunction 1 ('}':_) = 1
+countBracketsForFunction n ('{':xs) = countBracketsForFunction (n + 1) xs
+countBracketsForFunction n ('}':xs) = countBracketsForFunction (n - 1) xs
+countBracketsForFunction n ('\\':_:xs) = countBracketsForFunction n xs
+countBracketsForFunction n (_:xs) = countBracketsForFunction n xs
+
 parseFunction :: Parser Expression
-parseFunction = Function <$> ((++) <$> (parseString "fn " <|> parseString "export fn") <*> parseAllCharUntil "\n};\n")
+parseFunction = Parser f
+    where
+        f str = case runParser (
+            Function <$>
+                ((++) <$>
+                    (parseString "fn " <|> parseString "export fn") <*>
+                    parseAllCharUntil "\n};\n")) str of
+            Nothing -> Nothing
+            Just (Function x, xs) -> case countBracketsForFunction 0 x of
+                0 -> Just (Function x, xs)
+                _ -> Nothing
+            Just _ -> Nothing
 
 parseAlias :: Parser Expression
 parseAlias = Alias <$> ((++) <$> parseString "alias " <*> parseAllCharUntil ";\n")
@@ -41,6 +62,12 @@ parseExpresion :: Parser Expression
 parseExpresion = parseAlias <|> parseFunction <|> parseComment
 
 parseAllExpression :: Parser [Expression]
-parseAllExpression = some p
+parseAllExpression = Parser f
     where
         p = parseExpresion <* many (parseAnyChar "\n")
+        f [] = Just ([], [])
+        f str = case runParser p str of
+            Nothing -> Nothing
+            Just (x, xs) -> case runParser parseAllExpression xs of
+                Nothing -> Nothing
+                Just (y, ys) -> Just (x : y, ys)

lvtc/test/Spec.hs

@@ -26,7 +26,7 @@ testParserHelper str restExpected expressionExpected =
     case runParser parseExpresion str of
         Just (parsed, rest) -> assertEqual str restExpected rest >>
             assertEqual str expressionExpected parsed
-        Nothing -> assertFailure ("Parsing failed: " ++ str)
+        Nothing -> assertFailure ("Parsing failed for: `" ++ str ++ "`")
 
 testParserHelperFail :: String -> IO ()
 testParserHelperFail str = case runParser parseExpresion str of