Issue with Data Structure of form: A | B Y Z

[esjmb]

Hi,
I have noticed an odd error in a derived instance of FromBSON (and possibly ToBSON) for a type with a particular structure. I illustrate below.

type Token = ByteString
type Secret = ByteString
data RateLimiting = NoLimiting | AnonLimiting | AuthorizedLimiting Token Secret
                     deriving (Eq, Ord, Read, Show, Generic, Typeable, Hashable, Binary, NFData)

ToBSON seems to work ok, the following being an example of what is generated (ie. show $ toBSON x):

[ : [ ByteString: Binary "jdfjf3j4jh3jh4"], : [ ByteString: Binary "jhj34j300"], _co: "AuthorizedLimiting"]

(I've changed the contents of each binary string value, but note that they are stored correctly). However, I note that the two name-value elements of AuthorizedLimiting both have an empty name.

If FromBSON is called on this BSON document, then what results is an instance of AuthorizedLimiting with both token and secret bytestrings set to the value associated with the first name-value pair.

A possible fix I guess might be to explicitly name the token and secret in the declaration, but I thought I'd raise this with you first, as I guess this is an example of a failure to correctly generate or extract from BSON.

thanks,
Stephen.