title: Why are Ruby method calls particularly slow (in comparison to other languages)?
body: <p>I'm trying to read about Ruby performance, and came across <a href="https://stackoverflow.com/questions/2529852/why-do-people-say-that-ruby-is-slow">this SO thread</a>, where one of the answers mentions that "method calls, one of the most common operations in Ruby, are particularly slow."</p>
  
  <p><a href="https://stackoverflow.com/questions/1011460/what-makes-ruby-slow">Another thread</a> mentions that "It does "late lookup" for methods, to allow for flexibility. This slows it down quite a bit. It also has to remember names per context to allow for eval, so its frames and method calls are slower."</p>
  
  <p>Can someone explain in more detail why Ruby method calls are particularly slow, and elaborate on the second thread? I'm not totally sure what late lookup is or why it's slow, and I don't know what names per context means or how it relates to frames and method calls.</p>
  
  <p>My (possibly incorrect) understanding is that since methods can be added or modified at runtime, the Ruby interpreter can never "remember" how to run a particular method, so it has to lookup the method every time while the program is running, and this is what is meant by method calls being slow. But corrections and more technical explanations would be great.</p>