From: dblack@...
Date: 2006-03-26T00:04:36+09:00
Subject: Re: require a certain version of the ruby interpreter

Hi --

On Sat, 25 Mar 2006, ara.t.howard@noaa.gov wrote:

> On Sat, 25 Mar 2006, Ross Bamford wrote:
>
>> def ensure_version(v)
>>  raise "need #{v}" if VERSION.split('.').zip(v.split('.')).any? {|a,b| a < 
>> b}
>> end
>> 
>> (given that we don't need to worry about two-digit versions of course).
>
>
>  harp:~ > cat a.rb
>  def ensure_version(v)
>    raise "need #{v}" if VERSION.split('.').zip(v.split('.')).any? {|a,b| a < 
> b}
>  end
>  ensure_version "1.8.4"
>
>
>  harp:~ > /usr/bin/ruby a.rb
>  a.rb:2:in `ensure_version': undefined method `zip' for ["1", "6", 
> "8"]:Array (NameError)
>          from a.rb:4
>
>
> my point is that this code does not 'ensure' version 1.8.4 - it blows up 
> unless
> version 1.8.x.

I think you've discovered Duck Versioning:

   [].zip([]) rescue NameError "You need a later Ruby"

:-)


David

-- 
David A. Black (dblack@wobblini.net)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

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