# File lib/spruz/partial_application.rb, line 17
    def partial(*args)
      if args.empty?
        dup
      elsif args.size > arity
        raise ArgumentError, "wrong number of arguments (#{args.size} for #{arity})"
      else
        f = lambda { |*b| call(*(args + b)) }
        f.instance_variable_set :@__arity__, arity - args.size
        f
      end
    end