I'm not talking about superficial syntax like map/filter for collections. The notion of keeping the majority of your code side-effect-free with immutability, b

I'm not talking about superficial syntax like map/filter for collections. The notion of keeping the majority of your code side-effect-free with immutability, built-in concurrency and message-passing as idiomatic parts of the language/ecosystem is to this day uncommon and partially impossible in Python/Ruby. http://blog.jenkster.com/2015/12/what-is-functional-programming.html http://blog.jenkster.com/2015/12/what-is-functional-programm...