From: Robert Klemme <bob.news@...>
Date: 2003-11-24T17:52:12+09:00
Subject: Re: A code snippet: Controlled retry


"Gennady" <bystr@mac.com> schrieb im Newsbeitrag
news:4BB0276B-1E4F-11D8-A73D-0003939AEA24@mac.com...
> On Nov 23, 2003, at 23:02, Gennady wrote:
>
> >
> > On Nov 23, 2003, at 22:11, Hal Fulton wrote:
> >
> >>   def try(quiet=true,times=5,secs=1,&block)
> >>     count = 0
> >>     catch :finished do
> >>       begin
> >>         block.call
> >>       rescue => err
> >>         puts "Error was: #{err}" if not quiet
> >>         count += 1
> >>         throw :finished if count > times
> >>         sleep secs
> >>         retry
> >>       end
> >>     end
> >>   end
> >
> >
> >   def try(quiet=true,times=5,secs=1,&block)
> >     return unless block
> >     times.times do
> >       begin
> >         return block.call
> >       rescue => err
> >         puts "Error was: #{err}" unless quiet
> >         sleep secs
> >       end
> >     end
> >   end
> >
>
> Oops, times.times should become times.next.times to function like the
> original. Also, when all attempts are exhausted, the last exception
> must be re-raised or another more appropriate one raised (boolean
> return would also do the trick).

Combining the two of them (i.e. times.next and re-raising) by simply
adding a line,
plus adding a check to allow for non-sleeping retries,
plus output parameter that can be an IO or an Array,
plus changed the first return to an exception in order to let the user
know he forgot something:

   def try(times=0, secs=nil, log=nil, &block)
     raise LocalJumpError, "no block given" unless block

     times.times do
       begin
         return block.call
       rescue => err
         log << "Error was: #{err}\n" if log
         sleep secs if secs
       end
     end

     block.call
   end

Cheers

    robert