[Haskell-cafe] Re: Composing monads

Luke Palmer lrpalmer at gmail.com
Fri Nov 23 19:02:31 EST 2007

On Nov 23, 2007 6:24 PM, Jules Bean <jules at jellybean.co.uk> wrote:
> ...i.e. I wouldn't be afraid of a lambda in a case like that. IME it's
> moderately common to have to do:
> mapM_ (\a -> some stuff >> something_with a >> some stuff) ll

This has terrible endweight.  In this imperativesque case, I'd write:

    forM_ li $ \a -> do
      some stuff
      something with a
      some stuff

Where forM_ is from Data.Foldable  (but is easily written as flip mapM_).


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