Re: ANNOUNCE ex11 release two

Joe Armstrong <joe@xxxxxxx> wrote:
> I have experimented with many different styles of callback handling
> and IMHO this is the best. If you want to do it with messages you can write 
> your top-level thing like this:
> 
>       B = swButton:make(Win ......)
>       S = self(),
>       B ! {onClick, fun(X) -> S ! {wrapper, X} end},
>       ...
> 
>       loop(...).
> 
>         
>         loop(...) ->
>          receive
>               {wrapper, X} ->
>                   Do something
>               ...
>          end

What about allowing the caller to use a term for the message
if they just want a message sent:

        B = swButton:make(Win ....),
        S = self(),
        B ! {onClick, {S, wrapper} end},

        loop () ->
                receive
                {wrapper, X} ->
                end,
                loop().

Easy to tell a tuple and a fun apart; if it is a tuple it is a
two tuple of {Pid, Tag}; which results in the message {Tag, X}
being sent to to Pid.  This way the caller doesn't need to
build a fun, and waste all the bytecode and memory on a fun to
just send itself a tagged message.

Of course, this is only really useful if a large number of apps
are written this way.  :)

-- 
Shawn.

  Getting there is only half as far as getting there and back.