This reminds me of when I learned to program on my casio calculator.
There was a function to detect a key press which would return a number identifying the pressed key.
I needed to map that number to the letter printed on the key to print it on the screen.
I don't remember whether there was no hashmap data structure or I just didn't know about it, but I implemented it with a serie of if.
The problem with that solution is that while mapping A was fast, Z was very slow because it was at the end of the list.
That is how I discovered divide and conquer/ dichotomy with if branches.
Just parameters that are functions, except that you can only have one per function.
I still fail to see the advantage of blocks over being able to pass functions as arguments like in other languages.
I wonder if it has a chance to replace chrono and jiff in the rust ecosystem.