Seems to me this discussion is missing one of the main points of the original post: a massive plug for an unfairly under-appreciated book:

  > "Let Over Lambda" 
  > (which is really quite scary to read - I can't say that I understand 
  > 100% of it - maybe 60% and I am very happy with that level of 
  > comprehension) -- you end up with an enormously powerful set of 
  > programming tools unlike anything else out there.

I really like this book too and recommend it.

http://letoverlambda.com/index.cl/toc