ByteString conversion classes

1 files changed, 45 insertions, 0 deletions

diff --git a/src/ConvertByteString.hs b/src/ConvertByteString.hs
new file mode 100644
index 0000000..6b8f39f
--- /dev/null
+++ b/src/ConvertByteString.hs
@@ -0,0 +1,45 @@
+module ConvertByteString (
+    ToByteString(..),
+    FromByteString(..),
+    ConvertByteString(..),
+    BA.ScrubbedBytes,
+) where
+
+import Data.ByteArray qualified as BA
+import Data.ByteString (ByteString)
+import Data.ByteString.Unsafe qualified as BS
+
+import Foreign.Ptr
+
+
+class ToByteString a where
+    toByteString :: a -> ByteString
+    withByteArray :: a -> (Ptr p -> IO b) -> IO b
+
+class FromByteString a where
+    fromByteString :: ByteString -> a
+
+class ConvertByteString a b where
+    convert :: a -> b
+
+
+instance ToByteString ByteString where
+    toByteString = id
+    withByteArray bs f = BS.unsafeUseAsCString bs (f . castPtr)
+
+instance FromByteString ByteString where
+    fromByteString = id
+
+instance ToByteString a => ConvertByteString a ByteString where
+    convert = toByteString
+
+
+instance ToByteString BA.ScrubbedBytes where
+    toByteString = BA.convert
+    withByteArray = BA.withByteArray
+
+instance FromByteString BA.ScrubbedBytes where
+    fromByteString = BA.convert
+
+instance BA.ByteArrayAccess a => ConvertByteString a BA.ScrubbedBytes where
+    convert = BA.convert