Proposal: Add Compositor class as superclass of Arrow

[Josef Svenningsson]

On 10/23/07, Ashley Yakeley <ashley at semantic.org> wrote:
> On Sun, 2007-10-21 at 22:04 +0200, apfelmus wrote:
> > Twan van Laarhoven wrote:
> > > My proposal would be the following. The important things are that:
> > >  1. It incorporates Conal's deep arrow,
> > >  2. as well as everything that is needed for functional
> > > references/lenses and bijective/invertible functions.
> >
> > I'd opt for more research for that proposal to answer the following
> > essential questions:
> > - Do the classes correspond to already-known categories, i.e. are the
> > class names optimal?
> > - What laws do we expect to hold?
> > - Are the signatures minimal, i.e. does there exist a smaller set of
> > combinators that still achieves the intended effect? Are the signatures
> > complete, i.e. can the intended effect always expressed with the given
> > combinators?
> > - Plenty and useful examples? At least enough examples that fit in the
> > fine grained hierarchy but cannot be fit into a coarser grained one so
> > as to demonstrate the necessity of a fine grained hierarchy.
>
> I tend to agree. Rather than being part of this change, it might be
> better for someone to work on this as a separate library, and then make
> a proposal to redefine the Arrow classes once it's well-understood and
> settled.
>
+1

/Josef