module Puppet::Parser::Functions
  newfunction(:delete_values, :type => :rvalue, :doc => <<-EOS
Deletes all instances of a given value from a hash.

*Examples:*

    delete_values({'a'=>'A','b'=>'B','c'=>'C','B'=>'D'}, 'B')

Would return: {'a'=>'A','c'=>'C','B'=>'D'}

      EOS
    ) do |arguments|

    raise(Puppet::ParseError,
          "delete_values(): Wrong number of arguments given " +
          "(#{arguments.size} of 2)") if arguments.size != 2

    hash, item = arguments

    if not hash.is_a?(Hash)
      raise(TypeError, "delete_values(): First argument must be a Hash. " + \
                       "Given an argument of class #{hash.class}.")
    end
    hash.dup.delete_if { |key, val| item == val }
  end
end