--- TODO: actually this function already exists in hs-java-0.3!
-lookupMethod :: B.ByteString -> Class Resolved -> Maybe (Method Resolved)
-lookupMethod name cls = look (classMethods cls)
+
+buildMethodID :: Class Direct -> Word16 -> MethodInfo
+buildMethodID cls idx = MethodInfo (ntName nt) rc (ntSignature nt)
+ where (rc, nt) = case constsPool cls M.! idx of
+ (CMethod rc' nt') -> (rc', nt')
+ (CIfaceMethod rc' nt') -> (rc', nt')
+ _ -> error "buildMethodID: something wrong. abort."
+
+buildStaticFieldID :: Class Direct -> Word16 -> StaticFieldInfo
+buildStaticFieldID cls idx = StaticFieldInfo rc (ntName fnt)
+ where (CField rc fnt) = constsPool cls M.! idx
+
+buildFieldOffset :: Class Direct -> Word16 -> (B.ByteString, B.ByteString)
+buildFieldOffset cls idx = (rc, ntName fnt)
+ where (CField rc fnt) = constsPool cls M.! idx
+
+buildClassID :: Class Direct -> Word16 -> B.ByteString
+buildClassID cls idx = cl
+ where (CClass cl) = constsPool cls M.! idx
+
+methodGetArgsCount :: Class Direct -> Word16 -> Word32
+methodGetArgsCount cls idx = fromIntegral $ length args