Proposal: refactor Arrow class

[Ross Paterson]

On Mon, Jul 16, 2012 at 05:14:05PM +0100, Twan van Laarhoven wrote:
> [...]
> Is either of these classes enough for the do/if sugar? Or do you also
> need (&&&) and (|||) for those?

For if or case you need premap and (|||).
For do you need premap and (&&&).

But if you have Category and premap, you can make (|||) from left,
and (&&&) from first.

> But maybe I am wanting too much at once. :)

That occurred to me too.