Re: The Paradox of Partial Parametricity

On 10 May 2013 14:52, Mark S. Miller <erights@google.com> wrote:
> An upper case type variable, e.g. T, is fully parametric. It may be a
> promise or non-promise.
> A lower case type variable, e.g. t, is constrained to be a non-promise. If
> you wish to think in conventional type terms, consider Any the top type
> immediately split into Promise and non-promise. Thus type parameter t is
> implicitly constrained to be a subtype of non-promise.

Mark, I'm afraid such a distinction makes absolutely no sense in a
world of structural types. How would you specify the set of "types
that aren't promises" in a way that is compatible with structural
subtyping?

/Andreas