Yes, first-class functions are what I mean. (I come from a lot of C# development, where functions-as-variables are called delegates.)

As for sugar, I agree that it's nice sometimes, but I disagree with extending exception handling specifically. Exceptions are for errors, such as sending data over a closed stream, or indexing an array out of bounds. This "condition system" pattern encourages using exceptions for logic flow. Because why pass a function all the way down the call stack when you can just throw an exception to request that data from higher in the call stack, right?

Exceptions are errors, and they should be treated as such in all cases.