require 'set'
require 'will_paginate/array'
 
## Everything below blatantly stolen from ActiveSupport  :o
 
unless Hash.instance_methods.include? 'except'
  Hash.class_eval do
    # Returns a new hash without the given keys.
    def except(*keys)
      rejected = Set.new(respond_to?(:convert_key) ? keys.map { |key| convert_key(key) } : keys)
      reject { |key,| rejected.include?(key) }
    end
 
    # Replaces the hash without only the given keys.
    def except!(*keys)
      replace(except(*keys))
    end
  end
end
 
unless Hash.instance_methods.include? 'slice'
  Hash.class_eval do
    # Returns a new hash with only the given keys.
    def slice(*keys)
      allowed = Set.new(respond_to?(:convert_key) ? keys.map { |key| convert_key(key) } : keys)
      reject { |key,| !allowed.include?(key) }
    end
 
    # Replaces the hash with only the given keys.
    def slice!(*keys)
      replace(slice(*keys))
    end
  end
end
 
unless String.instance_methods.include? 'constantize'
  String.class_eval do
    def constantize
      unless /\A(?:::)?([A-Z]\w*(?:::[A-Z]\w*)*)\z/ =~ self
        raise NameError, "#{self.inspect} is not a valid constant name!"
      end
 
      Object.module_eval("::#{$1}", __FILE__, __LINE__)
    end
  end
end
 
unless String.instance_methods.include? 'underscore'
  String.class_eval do
    def underscore
      self.to_s.gsub(/::/, '/').
        gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
        gsub(/([a-z\d])([A-Z])/,'\1_\2').
        tr("-", "_").
        downcase
    end
  end
end