FW: RE [Haskell-cafe] Monad Description For Imperative Programmer

Jeff Polakow jeff.polakow at db.com
Wed Aug 1 17:11:24 EDT 2007


> 'Monad' is a type class.
> So what's 'IO'? Is the correct terminology 'instance' as in 'IO is an
> instance of Monad'. I consider 'IO' to be 'a monad' as that fits with
> mathematical terminology. 
I agree with this.

>But what about an actual object of type 'IO
> Int', say? 
I usually describe the type resulting from applying a monad a computation. 
Then 'IO Int' would be something like an IO computation of an Int. This 
terminology also jibes well with, or rather comes from, Moggi's 
computational lambda calculus (one of the early papers showing uses of 
Monads to computer science).



This e-mail may contain confidential and/or privileged information. If you 
are not the intended recipient (or have received this e-mail in error) 
please notify the sender immediately and destroy this e-mail. Any 
unauthorized copying, disclosure or distribution of the material in this 
e-mail is strictly forbidden.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.haskell.org/pipermail/haskell-cafe/attachments/20070801/497e0f9b/attachment.htm

More information about the Haskell-Cafe mailing list