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

@@ -1,3 +1,5 @@
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DerivingVia #-}
 module Ubc.Parse.Syntax.File
 ( File(..)
 , parse
@@ -17,36 +19,32 @@ 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, Generically(..))
+import Data.Functor ((<&>))
 
-data File = File 
+data File = File
         { name :: String
-        , structs :: [Struct]
+        , body :: FileBody
+        }
+        deriving (Show)
+
+data FileBody = FileBody
+        { structs :: [Struct]
         , functions :: [Function]
         , statements :: [Statement]
         , enumerations :: [Enumeration]
         }
-        deriving (Show)
+        deriving stock (Show, Generic)
+        deriving (Semigroup, Monoid) via Generically FileBody
+-- dont use `deriving ... via FileBody` because that leads to a loop, somehow
 
-data FileMember = FileFunction Function
+parse :: Monad m => String -> ParsecT String u m File
-        | FileStruct Struct
+parse source = File source <$!> mconcat <$!> many fileMember
-        | FileEnumeration Enumeration
-        | FileStatement Statement
 
-accumulateFile :: File -> FileMember -> File
+fileMember :: Monad m => ParsecT String u m FileBody
-accumulateFile (File name_ sss fs sts es) (FileStruct s)       = File name_ (s:sss) fs        sts     es
+fileMember = choice
-accumulateFile (File name_ sss fs sts es) (FileFunction f)     = File name_    sss  (f:fs)    sts     es
+                [ Struct.parse      <&> \s -> mempty { structs = [s] }
-accumulateFile (File name_ sss fs sts es) (FileStatement s)    = File name_    sss  fs     (s:sts)    es
+                , Function.parse    <&> \f -> mempty { functions = [f] }
-accumulateFile (File name_ sss fs sts es) (FileEnumeration e)  = File name_    sss  fs        sts  (e:es)
+                , Statement.parse   <&> \s -> mempty { statements = [s] }
-
+                , Enumeration.parse <&> \e -> mempty { enumerations = [e] }
-parse :: Monad m => ParsecT String u m File
-parse = foldr (flip accumulateFile) (File "" [] [] [] []) <$!> many fileMember
-
-fileMember :: Monad m => ParsecT String u m FileMember
-fileMember = choice 
-                [ FileStruct <$!> Struct.parse
-                , FileFunction <$!> Function.parse
-                , FileStatement <$!> Statement.parse
-                , FileEnumeration <$!> Enumeration.parse
                 ]
-
-        

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