1 files changed, 45 insertions, 0 deletions

diff --git a/examples/devel/example/wrappers.hs b/examples/devel/example/wrappers.hs
new file mode 100644
index 0000000..f4e0f0b
--- /dev/null
+++ b/examples/devel/example/wrappers.hs
@@ -0,0 +1,45 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE GADTs #-}
+
+{-
+    $ ghc -O2 wrappers.hs functions.c
+    $ ./wrappers
+-}
+
+import Numeric.LinearAlgebra
+import Numeric.LinearAlgebra.Devel
+import System.IO.Unsafe(unsafePerformIO)
+import Foreign.C.Types(CInt(..))
+import Foreign.Ptr(Ptr)
+
+
+infixl 1 #
+a # b = apply a b
+{-# INLINE (#) #-}
+
+infixr 5 :>, ::>
+type (:>)  t r = CInt -> Ptr t -> r
+type (::>) t r =  CInt -> CInt -> CInt -> CInt -> Ptr t -> r
+type Ok = IO CInt
+
+-----------------------------------------------------
+
+x = (3><5) [1..]
+
+main = do
+    print   x
+    print $ myDiag x
+    print $ myDiag (tr x)
+
+-----------------------------------------------------
+foreign import ccall unsafe "c_diag" cDiag :: Double ::> Double :> Double ::> Ok
+
+myDiag m = unsafePerformIO $ do
+    y <- createVector (min r c)
+    z <- createMatrix RowMajor r c
+    cDiag # m # y # z #| "cDiag"
+    return (y,z)
+  where
+    (r,c) = size m
+