3 files changed, 29 insertions, 35 deletions

diff --git a/lib/Data/Packed/Internal/Common.hs b/lib/Data/Packed/Internal/Common.hs
index 1212968..5548285 100644
--- a/lib/Data/Packed/Internal/Common.hs
+++ b/lib/Data/Packed/Internal/Common.hs
@@ -1,4 +1,4 @@
-{-# OPTIONS_GHC -fglasgow-exts -fallow-undecidable-instances #-}
+{-# OPTIONS_GHC -fglasgow-exts #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Data.Packed.Internal.Common
@@ -23,13 +23,6 @@ import Data.List(transpose,intersperse)
 import Data.Typeable
 import Data.Maybe(fromJust)
 
-debug x = trace (show x) x
-
-data Vector t = V { dim  :: Int
-                  , fptr :: ForeignPtr t
-                  , ptr  :: Ptr t
-                  } -- deriving Typeable
-
 ----------------------------------------------------------------------
 instance (Storable a, RealFloat a) => Storable (Complex a) where    --
     alignment x = alignment (realPart x)                            --
@@ -40,6 +33,8 @@ instance (Storable a, RealFloat a) => Storable (Complex a) where    --
     poke p (a :+ b) = pokeArray (castPtr p) [a,b]                   --
 ----------------------------------------------------------------------
 
+debug x = trace (show x) x
+
 on :: (a -> a -> b) -> (t -> a) -> t -> t -> b
 on f g = \x y -> f (g x) (g y)
 
@@ -55,13 +50,12 @@ common f = commonval . map f where
     commonval [a] = Just a
     commonval (a:b:xs) = if a==b then commonval (b:xs) else Nothing
 
-xor :: Bool -> Bool -> Bool
-xor a b = a && not b || b && not a
-
 (//) :: x -> (x -> y) -> y
 infixl 0 //
 (//) = flip ($)
 
+-- our codes should start from 1024
+
 errorCode :: Int -> String
 errorCode 1000 = "bad size"
 errorCode 1001 = "bad function code"
@@ -71,25 +65,6 @@ errorCode 1004 = "singular"
 errorCode 1005 = "didn't converge"
 errorCode n    = "code "++show n
 
-check :: String -> [Vector a] -> IO Int -> IO ()
-check msg ls f = do
-    err <- f
-    when (err/=0) (error (msg++": "++errorCode err))
-    mapM_ (touchForeignPtr . fptr) ls
-    return ()
-
---class (Storable a, Typeable a) => Field a
---instance (Storable a, Typeable a) => Field a
-
---isReal :: (Data.Typeable.Typeable a) => (t -> a) -> t -> Bool
---isReal w x   = typeOf (undefined :: Double) == typeOf (w x)
-
---isComp :: (Data.Typeable.Typeable a) => (t -> a) -> t -> Bool
---isComp w x = typeOf (undefined :: Complex Double) == typeOf (w x)
-
---scast :: forall a . forall b . (Typeable a, Typeable b) => a -> b
---scast = fromJust . cast
-
 {- | conversion of Haskell functions into function pointers that can be used in the C side
 -}
 foreign import ccall "wrapper" mkfun:: (Double -> Ptr() -> Double) -> IO( FunPtr (Double -> Ptr() -> Double)) 
diff --git a/lib/Data/Packed/Internal/Vector.hs b/lib/Data/Packed/Internal/Vector.hs
index f2646a4..0d9dc70 100644
--- a/lib/Data/Packed/Internal/Vector.hs
+++ b/lib/Data/Packed/Internal/Vector.hs
@@ -21,6 +21,28 @@ import Complex
 import Control.Monad(when)
 import Data.List(transpose)
 import Debug.Trace(trace)
+import Foreign.C.String(peekCString)
+import Foreign.C.Types
+
+
+data Vector t = V { dim  :: Int
+                  , fptr :: ForeignPtr t
+                  , ptr  :: Ptr t
+                  }
+
+check :: String -> [Vector a] -> IO Int -> IO ()
+check msg ls f = do
+    err <- f
+    when (err/=0) $ if err > 999 -- FIXME, it should be 1024
+                      then (error (msg++": "++errorCode err))
+                      else do
+                        ps <- gsl_strerror err
+                        s <- peekCString ps
+                        error (msg++": "++s)
+    mapM_ (touchForeignPtr . fptr) ls
+    return ()
+
+foreign import ccall "aux.h gsl_strerror" gsl_strerror :: Int -> IO (Ptr CChar)
 
 type Vc t s = Int -> Ptr t -> s
 -- not yet admitted by my haddock version
@@ -30,8 +52,6 @@ type Vc t s = Int -> Ptr t -> s
 vec :: Vector t -> (Vc t s) -> s
 vec v f = f (dim v) (ptr v)
 
---baseOf v = (v `at` 0)
-
 createVector :: Storable a => Int -> IO (Vector a)
 createVector n = do
     when (n <= 0) $ error ("trying to createVector of dim "++show n)
@@ -86,8 +106,6 @@ infixl 9 @>
 (@>) = at
 
 
-
-
 -- | creates a new Vector by joining a list of Vectors
 join :: Storable t => [Vector t] -> Vector t
 join [] = error "joining zero vectors"
@@ -111,7 +129,6 @@ asReal v = V { dim = 2*dim v, fptr =  castForeignPtr (fptr v), ptr = castPtr (pt
 asComplex :: Vector Double -> Vector (Complex Double)
 asComplex v = V { dim = dim v `div` 2, fptr =  castForeignPtr (fptr v), ptr = castPtr (ptr v) }
 
-
 ----------------------------------------------------------------
 
 liftVector :: (Storable a, Storable b) => (a-> b) -> Vector a -> Vector b
diff --git a/lib/Data/Packed/Internal/aux.h b/lib/Data/Packed/Internal/aux.h
index d055d35..83111e5 100644
--- a/lib/Data/Packed/Internal/aux.h
+++ b/lib/Data/Packed/Internal/aux.h
@@ -24,3 +24,5 @@ int submatrixR(int r1, int r2, int c1, int c2, KRMAT(x),RMAT(r));
 
 int diagR(KRVEC(d),RMAT(r));
 int diagC(KCVEC(d),CMAT(r));
+
+const char * gsl_strerror (const int gsl_errno);