[erlang-questions] A Generic API for controlling software components

[Richard O'Keefe]

On Nov 25, 2009, at 10:56 PM, Joe Armstrong wrote:
>    Rule4: All components C must have a file called	
>
>           $HOME/eComponents/C.ec/Preferences.pl
> 	
> 	   The extension .pl means the file contains a property
>           list. Here is an example:

We already have .pl meaning Prolog and .pl meaning Perl.
Since the property list uses Erlang syntax, how about
.epl (Erlang Property List)?
>
>     Rule6: Code upgrade
>
>           We should upgrade an component C when it's expiry date has
>           been reached. To update an component we delete the entire
>           component under $HOME/eComponents/C.ec we install the
>           new component and run the command: C:install().

What happens if the expiry date is reached and there _isn't_ any
new version, or the site the new version should be obtained from
is unreachable?
>

There are many kinds of components.
For example,
  - there should be exactly one instance
  - there should be at most one instance
  - there can be up to N instances to share work
  - there should be one instance per client
...
It isn't clear to me what range of component types this proposal
is meant to cover.