I have the following code:

```
data APNSIdentifier = NoIdentifier | Identifier Word32 deriving (Show, Eq)
newtype APNSItem = Item Put
createNotificationIdentifierItem :: APNSIdentifier -> APNSItem <--- here
createNotificationIdentifierItem (Identifier identifier) = do
putWord8 3
putWord16be 4
putWord32be identifier
```

How can I "wrap" the `Put`

monad with an `APNSItem`

? Do I have to make `APNSItem`

an instance of the `Monad`

typeclass or is there a simpler solution?

Answer:

```
createNotificationIdentifierItem :: APNSIdentifier -> APNSItem
createNotificationIdentifierItem (Identifier identifier) = Item $ do
putWord8 3
putWord16be 4
putWord32be identifier
```

or

```
createNotificationIdentifierItem :: APNSIdentifier -> APNSItem
createNotificationIdentifierItem (Identifier identifier) = do
Item $ putWord8 3
Item $ putWord16be 4
Item $ putWord32be identifier
```

after making `APNSItem`

an instance of `Monad`

(you can do this with `GeneralizedNewtypeDeriving`

, but you'll need to fix `APNSItem`

to have a single type variable first)

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