From: Srijayanth Sridhar <srijayanth@...>
Date: 2009-04-15T21:14:42+09:00
Subject: Re: OptionParser and Exceptions

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Thanks both of you.

Jayanth

On Wed, Apr 15, 2009 at 5:35 PM, Robert Klemme
<shortcutter@googlemail.com>wrote:

> 2009/4/15 Srijayanth Sridhar <srijayanth@gmail.com>:
> > Hello,
> >
> > The following code:
> >
> > require 'optparse'
> >
> > optparser = OptionParser.new do |args|
> >        list=[:foo,:bar,:baz]
> >        begin
> >                args.on("--l [OPTION]",list,"Blah") { |o| }
> >        rescue
> >                puts "Rescuing in the block"
> >        end
>
> This rescue does not make sense.  Because the code is invoked once
> upon OptionParser.new.  Parsing errors are thrown from parse and
> parse!.
>
> > end
> >
> > begin
> >        optparser.parse!(ARGV)
> > rescue
> >        puts "Rescuing in main"
> > end
> >
> > ./foo.rb -l FOO ends up being rescued in main.
> >
> > Why is this? the parse! method just calls the block defined in new
> doesn't
> > it? In which case, a begin and rescue block should work there right? Even
> if
> > I remove the begin and rescue block in main, it doesn't get rescued at
> all,
> > it just ends up spitting the usual ugly error etc.
>
> You need to rescue Exception because rescue without any arguments only
> rescues RuntimeErrors IIRC, it definitively does not catch every sub
> class of Exception.
>
> Cheers
>
> robert
>
> --
> remember.guy do |as, often| as.you_can - without end
> http://blog.rubybestpractices.com/
>
>

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