feat[classfile]: PrettySerialize instances

only a little bit broken formatting

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "3rdparty/pretty-parse"]
+	path = 3rdparty/pretty-parse
+	url = https://git.jossco.de/vegowotenks/pretty-parse

3rdparty/pretty-parse

@@ -0,0 +1 @@
+Subproject commit 93473c9ac69c20053d9fbe1b8a0ee199980cc435

app/Main.hs

@@ -4,6 +4,8 @@
 module Main (main) where
 
 import Data.ByteString.Lazy qualified as ByteString
+import Data.Text.Lazy.IO qualified as LazyTextIO
+import Pretty.Serialize qualified as Pretty
 
 import Language.Java.Classfile (Classfile)
 import Language.Java.Classfile.Extract (runExtract)
@@ -13,4 +15,4 @@ import Language.Java.Classfile.Stage (Stage(Parse))
 main :: IO ()
 main = do
   input <- ByteString.getContents
-  print $ runExtract input (extract @(Classfile Parse))
+  LazyTextIO.putStrLn . Pretty.serialize $ runExtract input (extract @(Classfile Parse))

java-classfile.cabal

@@ -44,12 +44,13 @@ library
       Paths_java_classfile
   hs-source-dirs:
       src
-  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -Wunused-packages
   build-depends:
       array
     , base >=4.7 && <5
     , bytestring
     , containers
+    , pretty-parse
     , text
   default-language: Haskell2010
 
@@ -59,13 +60,12 @@ executable java-classfile-exe
       Paths_java_classfile
   hs-source-dirs:
       app
-  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -Wunused-packages -threaded -rtsopts -with-rtsopts=-N
   build-depends:
-      array
-    , base >=4.7 && <5
+      base >=4.7 && <5
     , bytestring
-    , containers
     , java-classfile
+    , pretty-parse
     , text
   default-language: Haskell2010
 
@@ -76,12 +76,9 @@ test-suite java-classfile-test
       Paths_java_classfile
   hs-source-dirs:
       test
-  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -Wunused-packages -threaded -rtsopts -with-rtsopts=-N
   build-depends:
-      array
-    , base >=4.7 && <5
+      base >=4.7 && <5
     , bytestring
-    , containers
     , java-classfile
-    , text
   default-language: Haskell2010

package.yaml

@@ -19,11 +19,8 @@ synopsis:            Multi-Stage classfile parsing and verification.
 description:         Please see the README on Forgejo at <https://git.jossco.de/vegowotenks/java-classfile#readme>
 
 dependencies:
-- array
 - base >= 4.7 && < 5
 - bytestring
-- containers
-- text
 
 ghc-options:
 - -Wall
@@ -35,9 +32,15 @@ ghc-options:
 - -Wmissing-home-modules
 - -Wpartial-fields
 - -Wredundant-constraints
+- -Wunused-packages
 
 library:
   source-dirs: src
+  dependencies:
+  - array
+  - containers
+  - pretty-parse
+  - text
 
 executables:
   java-classfile-exe:
@@ -49,6 +52,8 @@ executables:
     - -with-rtsopts=-N
     dependencies:
     - java-classfile
+    - pretty-parse
+    - text
 
 tests:
   java-classfile-test:

src/Language/Java/Classfile.hs

@@ -29,6 +29,7 @@ import Language.Java.Classfile.Fields (Fields)
 import Language.Java.Classfile.Methods (Methods)
 import Language.Java.Classfile.Attributes (Attributes)
 import Data.Word (Word16)
+import Pretty.Serialize (PrettySerialize)
 
 
 -- | 'Stage'-indexed classfile. It can represent a class, an interface or a module.
@@ -50,6 +51,7 @@ data Classfile stage = Classfile
 
 deriving instance (Show (Magic stage), Show (ConstantPool stage), Show (ClassFlags stage), Show (Class stage)) => Show (Classfile stage)
 deriving via Generically (Classfile Parse) instance (Extractable (Classfile Parse))
+deriving via Generically (Classfile Parse) instance (PrettySerialize (Classfile Parse))
 
 type ClassFlags :: Stage -> Type
 data family ClassFlags stage
@@ -57,6 +59,7 @@ data family ClassFlags stage
 newtype instance ClassFlags Parse = ClassFlags (Flags ClassFlag)
   deriving stock (Show, Generic)
   deriving Extractable via Generically (ClassFlags Parse)
+  deriving PrettySerialize via Generically (ClassFlags Parse)
 
 data ClassFlag
   = Public      -- ^ may be accessed from outside the package
@@ -68,7 +71,8 @@ data ClassFlag
   | Annotation  -- ^ is annotation interface
   | Enum        -- ^ enumerated instances
   | Module      -- ^ module, not a class
-  deriving (Show, Eq, Ord, Enum, Bounded)
+  deriving (Show, Eq, Ord, Enum, Bounded, Generic)
+  deriving PrettySerialize via Generically ClassFlag 
 
 instance FlagMask ClassFlag where
   type FlagType ClassFlag = Word16

src/Language/Java/Classfile/Attributes.hs

@@ -10,6 +10,7 @@ import Language.Java.Classfile.Extractable (Extractable)
 import Language.Java.Classfile.ConstantPool.References (Utf8Reference)
 import Language.Java.Classfile.Extractable.SizedBytes (SizedBytes)
 import GHC.Generics ( Generic, Generically(..) )
+import Pretty.Serialize (PrettySerialize)
 
 -- | Generic Attribute array used everywhere.
 --
@@ -17,7 +18,7 @@ import GHC.Generics ( Generic, Generically(..) )
 
 newtype Attributes = Attributes (Array Word16 Attribute)
   deriving stock (Show)
-  deriving newtype Extractable
+  deriving newtype (Extractable, PrettySerialize)
 
 -- | Unknown Attribute
 
@@ -26,4 +27,4 @@ data Attribute = Attribute
   , info :: SizedBytes Word32
   }
   deriving stock (Show, Generic)
-  deriving Extractable via Generically Attribute
+  deriving (Extractable, PrettySerialize) via Generically Attribute

src/Language/Java/Classfile/ConstantPool.hs

@@ -1,6 +1,5 @@
 -- | THE constant pool, all the constants in a class file are handled in here.
 
-{-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE OverloadedStrings #-}
@@ -10,6 +9,8 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE DeriveGeneric #-}
 module Language.Java.Classfile.ConstantPool (ConstantPool(..)) where
 import Data.Word (Word16)
 import Data.Array.IArray (Array, listArray)
@@ -19,13 +20,19 @@ import Language.Java.Classfile.Extract (Extract, traceIndex, traceType)
 import qualified Data.Text as Text
 import Language.Java.Classfile.Stage (Stage(..))
 import Data.Kind (Type)
+import GHC.Generics (Generically(..), Generic)
+import Pretty.Serialize (PrettySerialize)
 
 type ConstantPool :: Stage -> Type
-data ConstantPool stage where
-  ConstantPool :: (Array Word16 Entry) -> ConstantPool Parse
-  NoPool :: ConstantPool Resolve
+data family ConstantPool stage
+
+newtype instance ConstantPool Parse = ConstantPool (Array Word16 Entry)
+  deriving stock (Generic, Show)
+
+deriving via (Generically (ConstantPool Parse)) instance PrettySerialize (ConstantPool Parse)
+
+data instance ConstantPool Resolve = NoPool
 
-deriving instance Show (ConstantPool stage)
 
 -- | 'Stage'-indexed constant-pool. The constant-pool is erased after resolving the class file.
 

src/Language/Java/Classfile/ConstantPool/Entry.hs

@@ -8,6 +8,7 @@
 {-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OrPatterns #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 module Language.Java.Classfile.ConstantPool.Entry (Entry(..), StorageCount(..), storageCount, MethodHandleInfo(..)) where
 import GHC.Generics (Generic, Generically(..))
 import Language.Java.Classfile.Extractable (Extractable (extract))
@@ -20,6 +21,7 @@ import Language.Java.Classfile.Extract (Extract, bytes)
 import qualified Data.Text.Encoding as Text
 import qualified Data.ByteString.Lazy as ByteString
 import qualified Data.ByteString as StrictByteString
+import Pretty.Serialize (PrettySerialize)
 
 -- | A single entry. Double and Long are not followed by something unusable, they are duplicated instead.
 
@@ -60,6 +62,7 @@ data Entry
   -- ^ Some package description
   deriving stock (Show, Generic)
   deriving Extractable via Generically Entry
+  deriving PrettySerialize via Generically Entry
 
 -- | Holds the invariants of MethodHandles (Only certain references are allowed after some kinds)
 --
@@ -68,11 +71,13 @@ data Entry
 data MethodHandleInfo = MethodHandleInfo MethodHandleReferenceKind OpaqueReference
   deriving stock (Show, Generic)
   deriving Extractable via Generically MethodHandleInfo
+  deriving PrettySerialize via Generically MethodHandleInfo
 
 -- | Extractor newtype for a java-utf-text with size tag specified as a type argument.
 
 newtype SizedText sizeType = SizedText Text
   deriving stock (Show)
+  deriving newtype PrettySerialize
 
 instance (Integral sizeType, Extractable sizeType) => Extractable (SizedText sizeType) where
   extract :: Extract (SizedText sizeType)

src/Language/Java/Classfile/ConstantPool/References.hs

@@ -7,6 +7,7 @@
 {-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE StandaloneKindSignatures #-}
+{-# LANGUAGE DeriveGeneric #-}
 module Language.Java.Classfile.ConstantPool.References (Utf8Reference(..), ClassReference(..), NameAndTypeReference(..), MethodHandleReferenceKind(..), OpaqueReference(..), BootstrapMethodIndex(..), Class) where
 import Data.Word (Word16, Word8)
 import Language.Java.Classfile.Extractable (Extractable)
@@ -14,12 +15,15 @@ import Language.Java.Classfile.Extractable.AsTag
     ( TagValue(..), AsTag, AsTag(..) )
 import Language.Java.Classfile.Stage (Stage(..))
 import Data.Kind (Type)
+import Pretty.Serialize (PrettySerialize)
+import GHC.Generics (Generically(..), Generic)
 
 -- | Wrapper for constant-pool reference to text.
 
 newtype Utf8Reference = Utf8Reference Word16
-  deriving stock (Show)
+  deriving stock (Show, Generic)
   deriving newtype Extractable
+  deriving PrettySerialize via Generically Utf8Reference
 
 -- | 'Stage'-indexed type, either a Class or only a t'ClassReference'.
 
@@ -30,26 +34,30 @@ type family Class stage where
 -- | Reference to a class in a constant-pool. This will resolve into a class.
 
 newtype ClassReference = ClassReference Word16
-  deriving stock (Show)
+  deriving stock (Show, Generic)
   deriving newtype Extractable
+  deriving PrettySerialize via Generically ClassReference
 
 -- | Reference to a class in a constant-pool. This will resolve to Name and Type.
 
 newtype NameAndTypeReference = NameAndTypeReference Word16
-  deriving stock (Show)
+  deriving stock (Show, Generic)
   deriving newtype Extractable
+  deriving PrettySerialize via Generically NameAndTypeReference
 
 -- | Reference to something in a constant-pool. I will hopefully get rid of this type.
 
 newtype OpaqueReference = OpaqueReference Word16
-  deriving stock (Show)
+  deriving stock (Show, Generic)
   deriving newtype Extractable
+  deriving PrettySerialize via Generically OpaqueReference
 
 -- | Reference to a method in the BootstrapMethods class attribute
 
 newtype BootstrapMethodIndex = BootstrapMethodIndex Word16
-  deriving stock (Show)
+  deriving stock (Show, Generic)
   deriving newtype Extractable
+  deriving PrettySerialize via Generically BootstrapMethodIndex
 
 -- | A Tag used to determine the type of a MethodHandle
 
@@ -63,8 +71,9 @@ data MethodHandleReferenceKind
   | InvokeSpecial
   | NewInvokeSpecial
   | InvokeInterface
-  deriving stock (Show, Enum, Bounded)
+  deriving stock (Show, Enum, Bounded, Generic)
   deriving Extractable via AsTag MethodHandleReferenceKind
+  deriving PrettySerialize via Generically MethodHandleReferenceKind
 
 instance TagValue MethodHandleReferenceKind where
   type TagType MethodHandleReferenceKind = Word8

src/Language/Java/Classfile/Extract.hs

@@ -2,17 +2,22 @@
 
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE InstanceSigs #-}
-{-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE DeriveGeneric #-}
 module Language.Java.Classfile.Extract (Extract(), bytes, runExtract, expectRaw, expectEqual, traceType, traceConstructor, traceField, traceIndex, Reason(..), Trace(..), Expected(..), Actual(..), TypeName(..)) where
 
 import Control.Applicative (Alternative (empty, (<|>)))
 import Control.Monad (MonadPlus)
 
+import GHC.Generics (Generic, Generically(..))
+
 import Data.ByteString.Lazy (ByteString)
 import Data.Text (Text)
 import Data.Typeable (Typeable, typeOf)
 
+import Pretty.Serialize (PrettySerialize)
+
 import qualified Data.ByteString.Lazy as ByteString
 import qualified Data.Text as Text
 
@@ -35,15 +40,18 @@ data Reply a
 
 -- | Type Alias for the Show instance
 newtype Expected = Expected Text
-  deriving Show
+  deriving stock (Show, Generic)
+  deriving PrettySerialize via Generically Expected
 
 -- | Type Alias for the Show instance
 newtype Actual = Actual Text
-  deriving Show
+  deriving stock (Show, Generic)
+  deriving PrettySerialize via Generically Actual
 
 -- | Type Alias for the Show instance
 newtype TypeName = TypeName Text
-  deriving Show
+  deriving stock (Show, Generic)
+  deriving PrettySerialize via Generically TypeName
 
 -- | Why did the computation fail?
 
@@ -56,7 +64,8 @@ data Reason
   -- ^ Something else went wrong
   | Unknown
   -- ^ Someone used the 'empty' function from 'Alternative'
-  deriving Show
+  deriving stock (Show, Generic)
+  deriving PrettySerialize via Generically Reason
 
 -- | Where did the computation fail? Calls to these functions are auto-generated by the Generic instances.
 
@@ -65,7 +74,8 @@ data Trace
   | InConstructor Text
   | InField Text
   | AtIndex Word
-  deriving Show
+  deriving stock (Show, Generic)
+  deriving PrettySerialize via Generically Trace
 
 instance Applicative Extract where
   -- | Don't consume any input

src/Language/Java/Classfile/Extractable/SizedBytes.hs

@@ -1,20 +1,22 @@
 -- | Read arbitrary bytes prefixed with a length.
 
-{-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE DerivingVia #-}
 module Language.Java.Classfile.Extractable.SizedBytes (SizedBytes(..)) where
 import Data.ByteString (ByteString)
 import Language.Java.Classfile.Extractable (Extractable (..))
 import Language.Java.Classfile.Extract (Extract, bytes)
 import qualified Data.ByteString as StrictByteString
 import qualified Data.ByteString.Lazy as ByteString
+import Pretty.Serialize (PrettySerialize, ShowPrettySerialize(..))
 
 -- | The sizeType type Paramter is used to extract the correct byte count.
 
 newtype SizedBytes sizeType = SizedBytes ByteString
   deriving stock Show
+  deriving PrettySerialize via ShowPrettySerialize (SizedBytes sizeType)
 
 instance (Extractable sizeType, Integral sizeType) => Extractable (SizedBytes sizeType) where
   extract :: Extract (SizedBytes sizeType)

src/Language/Java/Classfile/Extractable/WithTag.hs

@@ -16,6 +16,7 @@ import Control.Monad (void)
 import Data.Proxy (Proxy(Proxy))
 import Data.Typeable ( Typeable )
 import Data.Word (Word8)
+import Pretty.Serialize (PrettySerialize)
 
 -- | Type alias if you use the same type a lot.
 
@@ -25,7 +26,7 @@ type Word8Tag value a = WithNumericTag value Word8 a
 
 type WithNumericTag :: Natural -> Type -> Type -> Type
 newtype WithNumericTag value tagType a = Tagged a
-  deriving newtype Show
+  deriving newtype (Show, PrettySerialize)
 
 instance (KnownNat value, Extractable a, Extractable tagType, Eq tagType, Num tagType, Show tagType, Typeable tagType) => Extractable (WithNumericTag value tagType a) where
   extract :: Extract (WithNumericTag value tagType a)

src/Language/Java/Classfile/Fields.hs

@@ -14,12 +14,13 @@ import GHC.Generics ( Generically, Generic, Generically(..) )
 import Language.Java.Classfile.Flags (Flags, FlagMask (..))
 import Language.Java.Classfile.ConstantPool.References (Utf8Reference)
 import Language.Java.Classfile.Attributes (Attributes)
+import Pretty.Serialize (PrettySerialize)
 
 -- | Word16-Array of Fields.
 
 newtype Fields = Fields (Array Word16 Field)
   deriving stock Show
-  deriving newtype Extractable
+  deriving newtype (Extractable, PrettySerialize)
 
 -- | All the access flags a field can have
 
@@ -33,7 +34,8 @@ data FieldFlag
   | Transient
   | Synthetic
   | Enumeration -- original "Enum"
-  deriving stock (Show, Eq, Ord, Enum, Bounded)
+  deriving stock (Show, Eq, Ord, Enum, Bounded, Generic)
+  deriving PrettySerialize via Generically FieldFlag
 
 instance FlagMask FieldFlag where
   type FlagType FieldFlag = Word16
@@ -58,4 +60,4 @@ data Field = Field
   , attribute  :: Attributes
   }
   deriving stock (Show, Generic)
-  deriving Extractable via Generically Field
+  deriving (Extractable, PrettySerialize) via Generically Field

src/Language/Java/Classfile/Flags.hs

@@ -7,6 +7,9 @@
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DefaultSignatures #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE StandaloneDeriving #-}
 module Language.Java.Classfile.Flags (Flags(..), FlagMask(..), containsFlag) where
 
 
@@ -21,11 +24,14 @@ import Language.Java.Classfile.Extractable (Extractable (extract))
 import Data.Kind (Type)
 import Control.Arrow ((>>>))
 import qualified Data.List as List
+import GHC.Generics (Generic, Generically(..))
+import Pretty.Serialize (PrettySerialize)
 
 -- | Using the 'FlagMask' instance of the type parameter, this will extract all the flags whose mask produced a non-zero value using '.&.'
 
 newtype Flags a = Flags (Set a)
-  deriving (Show)
+  deriving (Show, Generic)
+deriving via Generically (Flags a) instance (PrettySerialize (Set a)) => PrettySerialize (Flags a)
 
 instance (Extractable (FlagType a), Bounded a, Enum a, Ord a, FlagMask a, Bits (FlagType a), Num (FlagType a)) => Extractable (Flags a) where
   extract :: Extract (Flags a)

src/Language/Java/Classfile/Interfaces.hs

@@ -8,9 +8,10 @@ import Data.Word (Word16)
 import Language.Java.Classfile.ConstantPool.References (ClassReference)
 import Language.Java.Classfile.Extractable (Extractable)
 import GHC.Generics ( Generic, Generically, Generically(..) )
+import Pretty.Serialize (PrettySerialize)
 
 -- | A list of classes something implements.
 
 newtype Interfaces = Interfaces (Array Word16 ClassReference)
   deriving stock (Show, Generic)
-  deriving Extractable via Generically Interfaces
+  deriving (Extractable, PrettySerialize) via Generically Interfaces

src/Language/Java/Classfile/Magic.hs

@@ -7,6 +7,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE DerivingVia #-}
 module Language.Java.Classfile.Magic (Magic(..)) where
 import Data.Word (Word32)
 import Language.Java.Classfile.Extractable (Extractable, extract, expectConstant)
@@ -14,6 +15,7 @@ import Language.Java.Classfile.Extract (Extract)
 import Data.Hex (Hex (Hex))
 import Language.Java.Classfile.Stage (Stage(Parse, Resolve))
 import Data.Kind (Type)
+import Pretty.Serialize (ShowPrettySerialize(ShowPrettySerialize), PrettySerialize)
 
 -- | 'Stage'-indexed Magic type. The 'Resolve' stage is only a unit type.
 
@@ -23,6 +25,7 @@ data Magic stage where
   Cafebabe :: Magic Resolve
 
 deriving instance Show (Magic stage)
+deriving via ShowPrettySerialize (Magic stage) instance PrettySerialize (Magic stage)
 
 instance Extractable (Magic Parse) where
   extract :: Extract (Magic Parse)

src/Language/Java/Classfile/Methods.hs

@@ -14,12 +14,13 @@ import Language.Java.Classfile.Extractable (Extractable)
 import GHC.Generics ( Generically, Generic, Generically(..) )
 import Language.Java.Classfile.ConstantPool.References (Utf8Reference)
 import Language.Java.Classfile.Attributes (Attributes)
+import Pretty.Serialize (PrettySerialize)
 
 -- | Alias for the methods structure from the constant-pool.
 
 newtype Methods = Methods (Array Word16 Method)
   deriving stock (Show)
-  deriving newtype Extractable
+  deriving newtype (Extractable, PrettySerialize)
 
 -- | A single method record, contains attributes, name and access flags.
 
@@ -30,7 +31,7 @@ data Method = Method
   , attributes  :: Attributes
   }
   deriving stock (Show, Generic)
-  deriving Extractable via Generically Method
+  deriving (Extractable, PrettySerialize) via Generically Method
 
 -- | Flags for the method, such as abstract, public or static.
 
@@ -47,7 +48,8 @@ data MethodFlag
   | Abstract
   | Strict
   | Synthetic
-  deriving stock (Show, Eq, Ord, Enum, Bounded)
+  deriving stock (Show, Eq, Ord, Enum, Bounded, Generic)
+  deriving PrettySerialize via Generically MethodFlag
 
 instance FlagMask MethodFlag where
   type FlagType MethodFlag = Word16

src/Language/Java/Classfile/Version.hs

@@ -7,6 +7,7 @@ module Language.Java.Classfile.Version (Version(..)) where
 import Data.Word (Word16)
 import GHC.Generics (Generic, Generically(Generically))
 import Language.Java.Classfile.Extractable (Extractable)
+import Pretty.Serialize (PrettySerialize)
 
 -- | Classfile versions only have two components. The minor component is zero since some java version.
 
@@ -15,7 +16,7 @@ data Version = Version
   , major :: Word16
   }
   deriving stock (Show, Generic)
-  deriving Extractable via Generically Version
+  deriving (Extractable, PrettySerialize) via Generically Version
 
 -- >>> import Language.Java.Classfile.Extractable (Extractable(extract))
 -- >>> import Language.Java.Classfile.Extract (runExtract, Extract)

stack.yaml

@@ -32,6 +32,7 @@ compiler: ghc-9.12.1
 #   - wai
 packages:
 - .
+- 3rdparty/pretty-parse
 # Dependency packages to be pulled from upstream that are not in the snapshot.
 # These entries can reference officially published versions as well as
 # forks / in-progress versions pinned to a git hash. For example: