From: Robert Klemme <bob.news@...>
Date: 2003-03-21T02:58:15+09:00
Subject: Re: class level Exception handling


"Mauricio Fern�ndez" <batsman.geo@yahoo.com> schrieb im Newsbeitrag
news:20030320164056.GA11459@student.ei.uni-stuttgart.de...
> On Fri, Mar 21, 2003 at 01:08:30AM +0900, Xiangrong Fang wrote:
> > Hi
> >
> > Could anyone teach me about the following?
> >
> > 1. in a File.open do ... end block, if I call break or return to exit
> > the block, will the file be closed?
>
> I guess yes, as it uses rb_ensure.

Right.

> module WrapMethod
>   def __block__(meth)
>     @blocks[meth]
>   end
>   def wrap(*args, &block)
>     @blocks ||= {}
>     args.each do |meth|
>       alias_method "__#{meth.to_s}__".intern, meth
>       @blocks[meth] = block
>       module_eval <<-EOF
>       def #{meth.to_s}(*args,&b)
>         begin
>           return __#{meth.to_s}__(*args,&b)
>         rescue Exception
>           return self.class.__block__(:#{meth.to_s}).call
>         end
>       end
>       EOF
>     end
>   end
> end

Did I miss something or do you store the same block in @block for each
method?  If so, why?  The original poster wanted to have a single error
handler for all methods.

Another suggestion I would make is to change the rescue clause to:

        rescue Exception => e
          return self.class.__block__(:#{meth.to_s}).call(e)
        end

and then

  wrap :foo, :bar, :baz do |ex|
    puts "Got #{ex.inspect}"
    false
  end

This is more explicit and provides for easier access to the exception,
because you need not remember that the exception is stored in $!.

Regards

    robert