[Haskell-beginners] What does "(# #)" mean?

[John M. Dlugosz]

On 4/5/2014 10:26 AM, Brandon Allbery wrote:
> On Sat, Apr 5, 2014 at 11:13 AM, John M. Dlugosz <ngnr63q02 at sneakemail.com
> <mailto:ngnr63q02 at sneakemail.com>> wrote:
>
>     The sources I've learned about thus far are not helping me with this one.
>     What's "(#   #)"?
>     Haskell is search-hostile.
>
>
> http://symbolhound.com :p

Hmm, I tried symbolhound, and only found pseudocode and parenthetical remarks that 
happened to begin with a #, or bullet points.

>
> It's an unboxed tuple, a type that is used internally (anything named with a # is GHC
> internals). You can't work with it normally (you need an extension to use the MagicHash),
> and it has a number of restrictions since most things require a constructor but an unboxed
> tuple doesn't have one.
>
> --
> brandon s allbery kf8nh                               sine nomine associates
> allbery.b at gmail.com <mailto:allbery.b at gmail.com> ballbery at sinenomine.net
> <mailto:ballbery at sinenomine.net>
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>
>