coercing newtypes

[Chris Okasaki]

Many of you have run across the problem with
newtypes that, although it is very cheap to
coerce between the newtype and the base type, it
can be very expensive to coerce between, say,
a list of the newtype and a list of the base type.
Stephanie Weirich and I are working on a proposal
for the Haskell Workshop addressing this problem,
and we would welcome any feedback from the community.

The current draft can be found at
  http://www.cs.columbia.edu/~cdo/coerce.ps.gz

--Chris