On Wed, Aug 26, 2015 at 8:14 PM, Tobias Dammers
IMO, having <- in do syntax look like assignment is bad enough as it is, no need to further enforce the illusion.
The syntax could be anything, it doesn't have to be an arrow. For example it could simply be an inbuilt function say `liftIdentity`. i.e. foo <- liftIdentity $ bar foo This makes sense if we think of every monad as a transformer around the Identity monad. Analogous to liftIO, except automatically defined for all Monads. Of course GHC would have to implement it in such a way so as to not use `return`.
The variable shadowing that effectively occurs in that example is still just as bad as regular shadowing.
I'm not sure how "shadowing" is bad. It is certainly safer than a string of foo, foo', foo'' etc.