Stream difference between Java 8 and 11

Stream.flatMap( ) causes breaking of short-circuiting of terminal operations -

it was a bug that was fixed starting from Java 10.

It is not a bug but an optimization to make flatMap work in lazy mode.

One of the beautiful feature improvement I can see, as now I can use flatMap in Lazy way, with almost fully supporting functional composition rather than just a chain of function execution (if not lazy).

Functional composition is what really excite me every day when I start writing NEW Java code.

Maybe I'm late to the party..!! :P

laziness has changed in case of flatMap, until java-10, flatMap was never lazy. see JDK-8075939