Extended maintenance of Ruby 1.9.3 ended on February 23, 2015. Read more
extension support for Context
# File irb/extend-command.rb, line 209 def self.def_extend_command(cmd_name, load_file, *aliases) line = __LINE__; Context.module_eval %[ def #{cmd_name}(*opts, &b) Context.module_eval {remove_method(:#{cmd_name})} require "#{load_file}" send :#{cmd_name}, *opts, &b end for ali in aliases alias_method ali, cmd_name end ], __FILE__, line end