> Anyway, I was always confused that Graham called this "bottom-up programming," because he explicitly goes top-down. He discovers a need at a higher level ("As

> Anyway, I was always confused that Graham called this "bottom-up programming," because he explicitly goes top-down. He discovers a need at a higher level ("As you're writing a program you may think 'I wish Lisp had such-and-such an operator'") and then he drops down to the lower level to provide it ("So you go and write it"). To me this is opposite of the approach that says you start at the bottom and implement a Platonic ideal of the domain, without first explicitly considering the needs of the program. This sums up why I've never really understood this essay. I agreed with the technique but was mystified by why it was called bottom up programming when you first had to approach the problem top down to discover what you needed to implement.