The most interesting part of this article for me is at the beginning. > Now imagine that calls could specify alternate return points, letting the callee decide

The most interesting part of this article for me is at the beginning. > Now imagine that calls could specify alternate return points, letting the callee decide the statement to return to: // Dreamed-up syntax fn f() { g() alternate |x| { dbg!(x); // x = 123 }; } fn g() -> () alternate i32 { return_alternate 123; } This sort of nonlocal control flow immediately calls to mind an implementation in terms of continuation passing style, where the return point is given as a function which is tail called. Nonlocal returns and multiple returns are easy to implement in this style. Does there exist a language where some function fn foo() -> T throws U is syntactic sugar for something more like? fn foo(ifOk: fn(T) -> !, ifExcept: fn(U) -> !) -> !