On Tue, Sep 20, 2011 at 1:22 PM, Jake McArthur <jake.mcarthur@gmail.com> wrote:

On Tue, Sep 20, 2011 at 3:48 PM, Chris Smith <cdsmith@gmail.com> wrote:
> But it would be the *wrong* thing to use as a desugaring for list range
> notation. List ranges are very unlikely to be useful or even meaningful
> for most such enumerations (what is [ Red, Green .. LightPurple]?); and
> conversely, as we've seen in this thread, list ranges *are* useful in
> situations where they are not a suitable way of enumerating all values
> of a type.

This makes me wonder if maybe the reason this discussion is happening
at all is that we don't have a well-defined meaning for what Enum
*is*.

Enum is the class that represents enumerable types. In other words, the class of things that can be injected into the natural numbers. These types inherit an order from the natural numbers, ordering by images under this injection.

Now, we might not like that order, and it might not agree with an Ord instance, but it exists.