From: Logan Capaldo <logancapaldo@...>
Date: 2004-11-03T11:20:20+09:00
Subject: Programmatically and dynamically catching exceptions

Allright here was my idea which seems to have been shattered by the
realities of Ruby.

I was thinking of a class called Try. You would do something like

class Try
...
end

tryblock = Try.new { #This block would normally be wrapped in a begin...rescue
                           }

tryblock.add_exhandler(:SomeException) { |ex| some_code }

tryblock.execute #or possibly tryblock.call ?

Basically the idea was going to be you could subclass Try and provide
default sensible handling of your Exceptions (if you were writing a
library for instance) . Users could then then wrap it in a
begin...rescue block to catch other exceptions or use add_exhandler to
overide the default handler. (Possibly provide a way to get the old
handler and and use it in the new).

my idea was going to be that I could do something like

begin
   user_proc.call
[SomeEx1, SomeEx2, etc..].each do |ex|
rescue ex => e
       handler_hash[ex].call(e)
end

Unfortunately the syntax doesn;t seem to allow for this. Am I missing
something? is this just a really bad idea?