> Hi Luke,
>
> join :: ByteString -> [ByteString] -> ByteString ???
>
> Vasili
>
> On Sat, Dec 27, 2008 at 1:58 AM, Luke Palmer <
lrpalmer@gmail.com> wrote:
>>
>> 2008/12/26 Galchin, Vasili <
vigalchin@gmail.com>
>>>
>>> Hello,
>>>
>>> I have a ByteString -> [ByteString] -> ByteString situation, i.e.
>>> concatenation .....
>>>
>>>
>>> -- marshall into ByteString representation
>>> join
>>> (encode (buildHeader
>>> ss)) -- ByteString
>>> (map encode (buildEntries (sequenceListExtract
>>> ss))) -- [ByteString]
>>>
>>>
>>> I get the following typecheck error which is vexing me ....
>>>
>>> Couldn't match expected type `t -> t -> B.ByteString'
>>> against inferred type `B.ByteString'
>>>
>>> ???
>>
>> join is not a function in Data.ByteString. By the error I'm guessing
>> you're getting the join from Control.Monad, instantiated to (->).
>> You are looking for "concat"; i.e.
>> concat $
>> encode (buildHeader ss) :
>> -- ByteString
>> map encode (buildEntries (sequenceListExtract ss))
>> -- [ByteString]
>>
>> (Control.Monad.join does end up meaning"concat" when working on lists of
>> lists, but it does not generalize to lists of other things).
>> Luke
>