This is why programming languages that support nesting really help in some scenarios. It's great to be able to write functions inside functions, with or without

This is why programming languages that support nesting really help in some scenarios. It's great to be able to write functions inside functions, with or without captured variables/bindings. (I know a tree isn't all graphs, but it works well for many scenarios.) When I start on a new program in F#, I usually just start with one main function and keep typing straight on down. When I want to re-organize it into a module, it's usually nearly as easy as writing "module" at the top. Without this, one is encouraged to either not abstract properly as the overhead and context for a new top-level function is too much, or you end up with free-floating functions that don't belong there and only have a single caller.