example/1.hear

@@ -1 +1 @@
-5*3+2
+5*3-2+-4-4

src/Main/Parser/Megaparsec.hs

@@ -23,7 +23,7 @@ symbol :: Text -> Parser Text
 symbol = L.symbol C.space
 
 int :: Parser Int
-int = lexeme L.decimal
+int = lexeme $ L.signed (return ()) L.decimal
 
 term :: Parser Expr
 term = Lit <$> int