On 10/27/06, matt neuburg <matt / tidbits.com> wrote:
> Some languages have a "with" construction, where undefined methods are
> routed to a designated object. Here's an example from UserTalk:
>
> with system.startup {
>    string(license)
> }
>
> UserTalk knows what "string" is, but when it can't find "license" it
> reinterprets it as system.startup.license, which works.

Barebones approach:

  system.startup.instance_eval do
    ...
  end

instance_eval sets "self" for the block so all messages with an
implicit receiver go to it's receiver.

> In UserTalk, you can even chain these tests:
>
> with system.temp, system.startup {
>    string(license)
> }

This is a little harder, in that you can't do it with one already
existing method, but it is possible. A way in which I can think of
doing it is to create a proxy instance that can contain multiple
target instances. The first target instance (they're ordered by
priority) that responds to the message will process it. A "with"
method that automatically creates this proxy around it's arguments
then instance_evals that block on the proxy would do what you're
looking for, I think.

The code to actually do the above is left as an exercise for the reader. ;)

Jacob Fugal