Re: bind :: Monad m => (a -> m b) -> m a -> m b

I’m +1 on this. Not only is it nice to sometimes have a non-operator (>>=) but it’s nice to have a function which more obviously lifts Kleisli arrows to monad arrows. Since it’s all aesthetics here, I think `bind f` is nice. Bob, ap is useful with the Monad constraint because it lets you define (<*>) just using an already written Monad instance. It looks like it’s staying that way too https://github.com/ghc/ghc/blob/master/libraries/base/GHC/Base.hs#L603 On Tue, Dec 9, 2014 at 4:55 PM, Bob Ippolito wrote:

+1 from me, I would love to have named versions of these operators. Does `ap` still have a Monad constraint or has it been changed to match the Applicative `<*>` after AMP? On Tue, Dec 9, 2014 at 1:44 PM, Christopher Done wrote:

...

Is this defined anywhere in base, and if not could it be placed in Control.Monad? I often find myself writing:

fmap (mu bar) (foo zot)

Then I decide to change the type of x, so instead I want to just write:

bind (mu bar) (foo zot)

Which is just like fmap but the function can run in the monad. Similar to traverse:

(Traversable t, Applicative f) => (a -> f b) -> t a -> f (t b)

As someone who isn’t a fan of operators, I generally am appreciative of alternative regular plain English word versions of functions, which I find easier to type, read and edit. Currently without defining such a handy name, I have to transform the code to this:

mu bar =<

The name for this function is a no-brainer:

bind :: Monad m => (a -> m b) -> m a -> m bbind = (=<<)

For comparison, the not-very-pleasant <$> and <*> each have word alternatives, fmap and ap. Even <> has mappend.

I don’t hold much hope for this, Haskellers love operators as much as Perl programmers so few on this list will see the value in plain old words, but at least I can link to this email in the archives for future reference.

Ciao ​

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