LAST CALL to comment on the Applicative/Monad Proposal

[Philippa Cowderoy]

On 18/12/2018 13:41, Henrik Nilsson wrote:
> Hi,
>
> Philippa wrote:
>
> > It's a lot easier to estimate ecosystem impact given a switch that'll
> > find all the resulting errors and give everyone a chance to fail any
> > tests.
>
> Yes, a good point.
>
> But just to be clear, the impact of some changes go well beyond what can
> be assessed by looking at impact on an existing code base alone.
> And that is one reason for why MRP has been, and remains, so
> controversial.


Sure. I think the one conceptual shift do-uses-*> would create is that 
do notation no longer (except in the degenerate tail case) always brings 
a Monad constraint, instead it would bring Applicative unless something 
is bound with <-. If I'm right then that's certainly a long way short of 
MRP per se, which I'm not interested in discussing at this point :)

I'm not sure how much of a problem that would create for teachers - I 
imagine it depends very much on one's style, as it can even reinforce 
the idea that Monad is partly about (unconstrained) binding! Which is a 
plus if you like making the connection to ANF to some extent and letting 
people think about a family of machine models. I think that's something 
it might even be nice to let students play with in some circumstances? 
Though I've done all my teaching 1:1 or with very small groups myself 
and generally not to first year undergraduates. Nor have I seen how AMP 
is affecting teaching in general properly.

Certainly something I'd be happy to talk about more if and when there's 
time - realistically there's no good reason to hold up AMP over this 
when it could be treated as a third proposal which depends on AMP and 
which MRP mandates. Should I find a TLA for it?

Is there somewhere else I should be pasting my thoughts here to? Any 
other comments? If I'm wasting people's time I'd rather stop, but if 
this is a viable proposal refactoring that might be another matter.

Cheers,
Philippa