Re: Signature of Control.Monad when and unless

On 24 August 2012 22:24, Stephen Tetley wrote:

Hasn't `void` recently been added to Base so that you can discard the result of any monadic action?

...

when True (void actionWithAnswer)

I also recall a similar discussion within the past six months on this topic, though I'm having difficulty finding it either online or in my emails :/ I believe the consensus of the previous discussion was that having functions such as your stated when_ and unless_ are dangerous in the general case due to the discarded results being implicitly ignored (same as how GHC nowadays throws warnings when statements in a do-block aren't of type m () ).

On 24 August 2012 10:12, Oren Ben-Kiki wrote: [CUT]

...

That is, I agree that results shouldn't be discarded "by default", but it should be easy to get rid of them if they are unneeded.

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