I'd be interested to see a concrete example of what you're talking about. Use a language, data structure, and function signature of your choice. My claim is th

I'd be interested to see a concrete example of what you're talking about. Use a language, data structure, and function signature of your choice. My claim is that in most cases, such a function can be implemented efficiently by chaining together standard higher-order functions (i.e. combinators), rather than by writing a custom tail recursive solution from scratch.