[Haskell-cafe] Beginners arrow question

Luke Palmer lrpalmer at gmail.com
Sat Apr 5 19:13:11 EDT 2008

On Sat, Apr 5, 2008 at 4:00 PM, Cale Gibbard <cgibbard at gmail.com> wrote:
>  GHC has a special syntax for using ArrowApply (which HXT is an
>  instance of). Whenever the expression to the left of -< needs to
>  involve a local variable, you can replace -< with -<< and it should
>  work. To understand better what it means, you can read
>  http://www.haskell.org/ghc/docs/latest/html/users_guide/arrow-notation.html

Sweet!  I didn't know that; I knew that ArrowApply gave you the
ability to use bindings
in the arrows, but it always bugged me that I couldn't even when I did
have an instance.
Go GHC! :-)


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