First, to make arguments that rely on syntax, one must use correct syntax. If OP’s syntax were valid, that return in the for-in would indeed exit the closure.

First, to make arguments that rely on syntax, one must use correct syntax. If OP’s syntax were valid, that return in the for-in would indeed exit the closure. To address this argument: the fact that a ‘return’ within a loop exits the enclosing function and a return from within a closure exits the closure is not a Swift problem.