License + GADT

java-classfile.cabal

@@ -1,4 +1,4 @@
-cabal-version: 2.2
+cabal-version: 1.12
 
 -- This file has been generated from package.yaml by hpack version 0.38.1.
 --
@@ -6,23 +6,18 @@ cabal-version: 2.2
 
 name:           java-classfile
 version:        0.1.0.0
-description:    Please see the README on GitHub at <https://github.com/githubuser/java-classfile#readme>
-homepage:       https://github.com/githubuser/java-classfile#readme
-bug-reports:    https://github.com/githubuser/java-classfile/issues
-author:         Author name here
+synopsis:       Multi-Stage classfile parsing and verification.
+description:    Please see the README on Forgejo at <https://git.jossco.de/vegowotenks/java-classfile#readme>
+author:         VegOwOtenks
 maintainer:     example@example.com
-copyright:      2025 Author name here
-license:        BSD-3-Clause
+copyright:      2025 VegOwOtenks
+license:        AGPL-3
 license-file:   LICENSE
 build-type:     Simple
 extra-source-files:
     README.md
     CHANGELOG.md
 
-source-repository head
-  type: git
-  location: https://github.com/githubuser/java-classfile
-
 library
   exposed-modules:
       Data.Enum.Util
@@ -47,8 +42,6 @@ library
       Language.Java.Classfile.Version
   other-modules:
       Paths_java_classfile
-  autogen-modules:
-      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
@@ -64,8 +57,6 @@ executable java-classfile-exe
   main-is: Main.hs
   other-modules:
       Paths_java_classfile
-  autogen-modules:
-      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
@@ -83,8 +74,6 @@ test-suite java-classfile-test
   main-is: Spec.hs
   other-modules:
       Paths_java_classfile
-  autogen-modules:
-      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

src/Language/Java/Classfile/Magic.hs

@@ -5,6 +5,7 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE StandaloneKindSignatures #-}
 {-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE GADTs #-}
 module Language.Java.Classfile.Magic (Magic(..)) where
 import Data.Word (Word32)
 import Language.Java.Classfile.Extractable (Extractable, extract, expectConstant)
@@ -16,13 +17,9 @@ import Data.Kind (Type)
 -- | 'Stage'-indexed Magic type. The 'Resolve' stage is only a unit type.
 
 type Magic :: Stage -> Type
-data family Magic stage
-
-newtype instance Magic Parse   = Magic (Hex Word32)
-  deriving Show
-
-data instance Magic Resolve = Cafebabe
-  deriving Show
+data Magic stage where
+  Magic :: Hex Word32 -> Magic Parse
+  Cafebabe :: Magic Resolve
 
 instance Extractable (Magic Parse) where
   extract :: Extract (Magic Parse)