オープンクラスでAOP風になるんですな。
class String alias org_length length def length puts "org => #{org_length}" result = org_length * 3 puts "result => #{result}" result end end 'abc'.length
org => 3
result => 9
class String alias org_length length def length puts "org => #{org_length}" result = org_length * 3 puts "result => #{result}" result end end 'abc'.length
org => 3
result => 9