[Haskell-beginners] Ignoring the result of a monadic computation

Isaac Dupree ml at isaac.cedarswampstudios.org
Sun Nov 21 13:48:11 EST 2010

On 11/19/10 10:21, Brent Yorgey wrote:
> On Fri, Nov 19, 2010 at 07:56:02AM +0100, Tim Baumgartner wrote:
>> using
>> ignore :: Monad m =>  m a ->  b ->  m b
>> ignore m a = m>>  return a
>> I'm satisfied with this solution but searching hoogle I didn't find
>> a standard function for my ignore. Am I missing something?
> Nope, there isn't such a function, but I like it.  It reminds me of
> (*>) and (<*) from Control.Applicative.

In fact, it is equal to: flip (<$)
with <$ from Control.Applicative
and it only needs a Functor constraint, not Monad or Applicative.

As y'all found out though, in this case an actual Applicative function 
looked like a cleaner way to write the parser.


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