The author doesn't mention laziness, which is pretty huge. Laziness is half of immutable data structures!
I have a tidbit in the first paragraphs: http://blog.vmchale.com/article/effects
I have a tidbit in the first paragraphs: http://blog.vmchale.com/article/effects
Certainly laziness has influenced a lot of things in the world of FP. But it's really helpful to distinguish laziness from FP, especially considering the problems that laziness introduces.