From: Ryan Leavengood <leavengood@...>
Date: 2005-11-05T11:31:54+09:00
Subject: Re: Optional block arguments?

On 11/4/05, Vincent Foley <vfoley@gmail.com> wrote:
> How can I have a block that optionally takes an argument?  Thanks.

irb(main):001:0> p = proc do |*a|
irb(main):002:1*   if a[0]
irb(main):003:2>     puts "Got parameter: #{a[0]}"
irb(main):004:2>   else
irb(main):005:2*     puts "No parameter"
irb(main):006:2>   end
irb(main):007:1> end
=> #<Proc:0x02b5d640@(irb):1>
irb(main):008:0> p.call
No parameter
=> nil
irb(main):009:0> p.call 1
Got parameter: 1
=> nil

Ryan