Let me point out another concern with autolifting: it makes it easy to
overlook sharing. In the pure world, sharing is unobservable; not so
when effects are involved.
Let me take the example using the code posted in your first message:
t1 = let x = 1 + 2 in x + x
The term t1 is polymorphic
Thank you for highlighting these problems; I should really test my own code
more thoroughly. After reading these most recent examples, the translation
to
existing monads is definitely too neat, and a lot of semantics of the monad
are
'defaulted' on. In particular for the probability monad examples
Ling Yang wrote
I think a good question as a starting point is whether it's possible
to do this 'monadic instance transformation' for any typeclass, and
whether or not we were lucky to have been able to instance Num so
easily (as Num, Fractional can just be seen as algebras over some base
Thanks Oleg for the feedback. If I understand right, there is a hard (as in
computability) limit for automatic instancing due to the general requirement of
deriving functions off of the behavior of another.
At this point, I wonder: How good are we at doing this? There's languages that
reside in
On Nov 16, 2010, at 12:36 PM, Ling Yang wrote:
Are only
'trivial' results possible, or that the incomputability problems are
just moved
into type space?
That's typically the case, under Rice's theorem.
A construct is derivable if it works for all cases (i.e., it's a free
theorem), or
