Tim Bray links to an article on functional programming that explains why it’s important.
I’m not sure I get functional programming yet — though I’m curious.
I also suspect that I may already be using functional programming principles. My parents taught me to eliminate side effects as a matter of good design way back in 1980. (Hello GOSUB!) Today I use blocks and GCD; I minimize state and mutability and I’m strict about what can change what.
I’m not really sure that functional programming is more than a set of old-fashioned solid practices that have gained more emphasis (quite rightly) in the age of concurrency.
But I suspect that a functional programming advocate would say that I’m at step 1: vague understanding, with a sense that some of this is familiar. That hypothetical advocate would agree that I don’t really get it yet.
I look forward to learning more.