From: Von Fugal <vontrapp@...>
Date: 2008-05-17T02:44:59+09:00
Subject: Re: Named sprintf parameters

Adam Shelly wrote:
<snip/>
> puts "\nMonkeyPatching!\n\n"
> class String
>   alias :old_percent :%
>   def % arg
>     arr = (arg.kind_of? Array) ? arg : [arg]
>     target = self.gsub(/%\((.+?)\)/){|m|
>       raise ArgumentError, "named parameters need hash" unless 
> arg.kind_of? Hash
>       arr << arg[$1.to_sym]
>       "%#{arr.size}$"
>     }
>     target.old_percent arr
>   end
> end
<snip/>

Don't forget the escaped %, and also, I propose the format %foo:s 
instead of %(foo)s. And heres some more code to chew on, based off of 
Adam's:

class String
  alias old_percent %
  def % arg
    names = []
    target = gsub /(^|[^%])%(\w+):/ do
      name, space = $2, $1 # don't forget to replace whatever wasn't %
      names << name unless names.include? name
      "#{space}%#{names.rindex(name) + 1}$"
    end
    args = case arg
      when Hash: names.map {|n| arg[n] or arg[n.to_sym]} #keys are often 
symbols
      when Array: arg
      else [arg]
    end
    old_percent args
  end
end
-- 
Posted via http://www.ruby-forum.com/.