(== 10)

Since Clojure uses the Java calling conventions, it cannot, and does not, make the same tail call optimization guarantees. Instead, it provides the recur special operator, which does constant-space recursive looping by rebinding and jumping to the nearest enclosing loop or function frame. While not as general as tail-call-optimization, it allows most of the same elegant constructs, and offers the advantage of checking that calls to recur can only happen in a tail position.

In Switzerland, one of my recent ancestors was functionally illiterate. Because of this, she “signed away” most of her wealth. Down the line, I’m one of her very few heirs. So, in a way, I lost part of my inheritance due to illiteracy.

Keeping unpure functions clearly named and organized in such a way that they can be easily identified versus pure functions is a common goal of modularizing and organizing Scala applications.

Much like a Unix power user will compose multiple single-purpose tools into a complex piped command, a functional programmer will combine single-purpose function invocations into chains of operations (think Map/Reduce).