Resolves issue with parsing comments

src/Parser.hs

@@ -1,16 +1,16 @@
 module Parser where
 
-import Debug.Trace
 import Lexer
 import Research hiding (toList)
-import Control.Exception (throw)
+
 import Data.List.NonEmpty (toList)
-import qualified Data.Set as Set
-import Data.Void
+import Data.Void (Void)
 import Text.Megaparsec
 import Text.Megaparsec.Char
 import Text.Megaparsec.Error (errorBundlePretty, ParseErrorBundle)
 
+import qualified Data.Set as Set
+
 type Parser = Parsec Void [LToken]
 
 data TricuAST
@@ -24,17 +24,24 @@ data TricuAST
   | TStem TricuAST
   | TFork TricuAST TricuAST
   | SLambda [String] TricuAST
+  | SEmpty
   deriving (Show, Eq, Ord)
 
 parseTricu :: String -> [TricuAST]
-parseTricu input =
-  let nonEmptyLines = filter (not . null) (lines input)
-  in map parseSingle nonEmptyLines
+parseTricu input
+  | null tokens = []
+  | otherwise = map parseSingle tokens
+  where
+    tokens = case lexTricu input of
+      [] -> []
+      tokens -> lines input
 
 parseSingle :: String -> TricuAST
-parseSingle input = case runParser parseExpression "" (lexTricu input) of
-  Left  err -> error $ handleParseError err
-  Right ast -> ast
+parseSingle input = case lexTricu input of
+  [] -> SEmpty
+  tokens -> case runParser parseExpression "" tokens of
+    Left err -> error $ handleParseError err
+    Right ast -> ast
 
 parseExpression :: Parser TricuAST
 parseExpression = choice