Stream: Exception Handling

Standard functional interfaces do not declare throws, so checked exceptions in lambdas require try-catch wrapping, a custom throwing interface, or a sneaky throw utility.

Stream functional interfaces cannot carry checked exceptions, so you must catch and rethrow as unchecked inside the lambda, or use a reusable wrapper utility.

`unchecked(CheckedFunction)` adapts a checked-throwing lambda into a stream-compatible `Function` by catching and rethrowing as unchecked.

Map each element to a success-or-error result object, then partition into successes and failures so one bad element does not abort the whole pipeline.