From 96bd2316525bb8790d4f047834c0ca6750155583 Mon Sep 17 00:00:00 2001
From: Ilya Portnov <portnov84@rambler.ru>
Date: Sun, 2 Oct 2011 19:12:42 +0600
Subject: [PATCH] Simplify some instances.

---
 JVM/Builder/Monad.hs | 2 +-
 JVM/ClassFile.hs     | 9 +++++----
 JVM/Converter.hs     | 2 +-
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/JVM/Builder/Monad.hs b/JVM/Builder/Monad.hs
index 85aaa5e..01e93f1 100644
--- a/JVM/Builder/Monad.hs
+++ b/JVM/Builder/Monad.hs
@@ -72,7 +72,7 @@ lookupPool :: Constant Direct -> Pool Direct -> Maybe Word16
 lookupPool c pool =
   fromIntegral `fmap` findIndex (== c) (M.elems pool)
 
-addNT :: Binary (Signature a) => NameType a -> Generate Word16
+addNT :: HasSignature a => NameType a -> Generate Word16
 addNT (NameType name sig) = do
   let bsig = encode sig
   x <- addItem (CNameType name bsig)
diff --git a/JVM/ClassFile.hs b/JVM/ClassFile.hs
index 0359320..2b7e1e7 100644
--- a/JVM/ClassFile.hs
+++ b/JVM/ClassFile.hs
@@ -128,7 +128,8 @@ data AccessFlag =
   deriving (Eq, Show, Ord, Enum)
 
 -- | Fields and methods have signatures.
-class HasSignature a where
+class (Binary (Signature a), Show (Signature a), Eq (Signature a))
+    => HasSignature a where
   type Signature a
 
 instance HasSignature Field where
@@ -142,12 +143,12 @@ data NameType a = NameType {
   ntName :: B.ByteString,
   ntSignature :: Signature a }
 
-instance Show (Signature a) => Show (NameType a) where
+instance (HasSignature a) => Show (NameType a) where
   show (NameType n t) = toString n ++ ": " ++ show t
 
-deriving instance Eq (Signature a) => Eq (NameType a)
+deriving instance HasSignature a => Eq (NameType a)
 
-instance (Binary (Signature a)) => Binary (NameType a) where
+instance HasSignature a => Binary (NameType a) where
   put (NameType n t) = putLazyByteString n >> put t
 
   get = NameType <$> get <*> get
diff --git a/JVM/Converter.hs b/JVM/Converter.hs
index 777bac6..5993d54 100644
--- a/JVM/Converter.hs
+++ b/JVM/Converter.hs
@@ -175,7 +175,7 @@ constantPoolArray ps = pool
 
     n = fromIntegral $ M.size ps
 
-    convertNameType :: (HasSignature a, Binary (Signature a)) => Word16 -> NameType a
+    convertNameType :: (HasSignature a) => Word16 -> NameType a
     convertNameType i =
       let (CNameType n s) = pool ! i
       in  NameType n (decode s)
-- 
2.25.1