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

[Christopher Allen]

The user meant unboxed tuples, not a literal string. Try not to give the
questioner the benefit of the doubt and search for a better answer than,
"there's quotes, it must be a string rather than them trying to contain the
syntax they want to express!"

Anyway, Haskell isn't search hostile, Google is Haskell hostile. You can
use Symbolhound to search for symbols in web pages.

Search I used to get your answer:
http://symbolhound.com/?q=tuple+%28%23+%23%29+Haskell

What is most likely your answer:
http://www.haskell.org/ghc/docs/latest/html/users_guide/primitives.html#unboxed-tuples

Further reading:

Kinds, reference types, and value types in Haskell. Also, Alan Watts.

Double is a reference type of Kind *

Double# is an unboxed value type of Kind #

Types in Haskell default to *. This is what you want usually. Value types
are an after-the-fact optimization that shouldn't be done without the
guidance of a well-designed benchmark suite.

But yeah, not a string.

--- Chris Allen



On Sat, Apr 5, 2014 at 10:20 AM, Emanuel Koczwara <poczta at emanuelkoczwara.pl
> wrote:

> Hi,
>
> Dnia 2014-04-05, sob o godzinie 10:13 -0500, John M. Dlugosz pisze:
> > The sources I've learned about thus far are not helping me with this one.
> > What's "(#   #)"?
> > Haskell is search-hostile.
> >
>
> Can you provide some context? It looks like ordinary string
>
>   "(#   #)" :: String
>
> or
>
>   "(#   #)" :: [Char]
>
> Emanuel
>
>
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