[Haskell-cafe] Why do I have to specify (Monad m) here again?

Bulat Ziganshin bulat.ziganshin at gmail.com
Sun Feb 18 13:50:18 EST 2007

Hello Marc,

Sunday, February 18, 2007, 8:05:24 PM, you wrote:

> Is there a difference at all wehter specifying (Monad m) in the class
> declaration or not? I have to add it to the instance declaration
> anyway..
> And if you don't want to change the meaning of instance declaration you
> would be able to add this constraint to indicate this.

> I don't see why it simplifies error messages.

i mean that it makes error message more obvious - you don't need to
remember that this context is implied due to class declaration

Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com

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