Proposal: Data.Proxy

[Neil Mitchell]

Hi

> I propose a module called Data.Proxy into the base package containing the common
> Proxy type used in many different libraries (e.g. HAppS, HList, ...).
>
> Attached is the source code.

Great idea!

A few questions:

Proxy is very simple, so why not export it as Proxy(..) - the
implementation of the data type is essential to how it works. We don't
hide things like Maybe's internals. It's not an abstract data type,
its a concrete one (in my mind).

If you do this, then proxy is redundant, we have Proxy on its own.

I would rather something like proxyOf than toProxy - this fits in
slightly better with asTypeOf in the Prelude.

Thanks

Neil