Fixed the infinite loop

app/Main.hs

@@ -6,4 +6,4 @@ main :: IO ()
 main = do
         text <- getContents
 
-        print $ Parsec.parse (File.parse <* Parsec.eof) "<stdin>" text 
+        print $ Parsec.parse (File.parse "<stdin>" <* Parsec.eof) "<stdin>" text 

src/Ubc/Parse/Syntax/File.hs

@@ -19,7 +19,7 @@ import qualified Ubc.Parse.Syntax.Struct as Struct
 import qualified Ubc.Parse.Syntax.Function as Function
 import qualified Ubc.Parse.Syntax.Statement as Statement
 import qualified Ubc.Parse.Syntax.Enumeration as Enumeration
-import GHC.Generics (Generic)
+import GHC.Generics (Generic, Generically(..))
 import Data.Functor ((<&>))
 
 data File = File
@@ -35,10 +35,11 @@ data FileBody = FileBody
         , enumerations :: [Enumeration]
         }
         deriving stock (Show, Generic)
-        deriving (Semigroup, Monoid) via FileBody
+        deriving (Semigroup, Monoid) via Generically FileBody
+-- dont use `deriving ... via FileBody` because that leads to a loop, somehow
 
-parse :: Monad m => ParsecT String u m File
+parse :: Monad m => String -> ParsecT String u m File
-parse = File "" <$!> mconcat <$!> many fileMember
+parse source = File source <$!> mconcat <$!> many fileMember
 
 fileMember :: Monad m => ParsecT String u m FileBody
 fileMember = choice

src/Ubc/Parse/Syntax/Struct.hs

@@ -7,7 +7,7 @@ module Ubc.Parse.Syntax.Struct
 where
 
 -- yay, explicit dependency on ghc
-import GHC.Generics (Generic)
+import GHC.Generics (Generic, Generically(..))
 
 import Control.Monad ((<$!>))
 
@@ -39,7 +39,7 @@ data StructBody = StructBody
         , functions :: [Function]
         }
         deriving stock (Generic, Show)
-        deriving (Semigroup, Monoid) via StructBody
+        deriving (Semigroup, Monoid) via Generically StructBody
 
 parse :: Monad m => ParsecT String u m Struct
 parse = do