Re: [Haskell-cafe] In " returnIO x = IO $ \ s -> (# s, x #)" what are the # symbols?

That's special syntax to make an unboxed tuple. See the manual section on unboxed types[1]. [1]: https://downloads.haskell.org/~ghc/7.6.3/docs/html/users_guide/primitives.ht... On Mon, Jul 13, 2015 at 5:23 PM, Jeffrey Brown wrote:

That appears here: http://hackage.haskell.org/package/base-4.8.0.0/docs/src/GHC-Base.html#line-...

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe