From: Joel VanderWerf <vjoel@...>
Date: 2006-03-26T06:08:12+09:00
Subject: Re: Verifying keyword arguments

Ross Bamford wrote:
...
> Not sure about libraries (though I'm sure they are out there, check RAA
> and Rubyforge) but here's a little trick I've used before:
> 
> args = { :one => 'two', :three => 'four' }
> # => {:three=>"four", :one=>"two"}
> 
> h = Hash.new { |h,k| raise ArgumentError, "#{k}" }.merge(args)
> # => {:three=>"four", :one=>"two"}
> 
> h[:one]
> # => "two"
> 
> h[:three]
> # => "four"
> 
> h[:two]
> ArgumentError: two
>         from (irb):5
>         from (irb):11
> 
> This way, you never actually check the arguments explicitly, but you'll
> be told if your method uses one that wasn't passed. Obviously for
> optional arguments you go to the original hash.
> 

What about using rescue for optional arguments? It might be slower though.

-- 
      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407