feat: MonadPlus instance for Extract

src/Language/Java/Classfile/Extract.hs

@@ -2,19 +2,25 @@
 
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE InstanceSigs #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE DeriveAnyClass #-}
 module Language.Java.Classfile.Extract (Extract(), bytes, runExtract, expectRaw, expectEqual, traceType, traceConstructor, traceField, traceIndex, Reason(..), Trace(..), Expected(..), Actual(..), TypeName(..)) where
 
-import Data.ByteString.Lazy (ByteString)
-import qualified Data.ByteString.Lazy as ByteString
 import Control.Applicative (Alternative (empty, (<|>)))
+import Control.Monad (MonadPlus)
+
+import Data.ByteString.Lazy (ByteString)
 import Data.Text (Text)
-import qualified Data.Text as Text
 import Data.Typeable (Typeable, typeOf)
 
+import qualified Data.ByteString.Lazy as ByteString
+import qualified Data.Text as Text
+
 -- | Extractor Monad. Computations running in this monad will automatically keep track of used resources and backtrack arbitrarily.
 
 newtype Extract a = Extract (Continuation a)
   deriving (Functor)
+  deriving anyclass MonadPlus
 
 -- | Functions work wonders when defining monads.