152. Introducing the sequence layout

In Problem 149, we already covered the ValueLayout for basic data types. Next, let’s talk about the sequence layout (java.lang.foreign.SequenceLayout).

But before introducing the sequence layout, let’s take a moment to analyze the following snippet of code:

try (Arena arena = Arena.ofConfined()) {
  MemorySegment segment = arena.allocate(
    ValueLayout.JAVA_DOUBLE.byteSize() * 10,
    ValueLayout.JAVA_DOUBLE.byteAlignment());
  for (int i = 0; i < 10; i++) {
    segment.setAtIndex(ValueLayout.JAVA_DOUBLE,
      i, Math.random());
  }
  for (int i = 0; i < 10; i++) {
    System.out.printf("\nx = %.2f",
      segment.getAtIndex(ValueLayout.JAVA_DOUBLE, i));
  }
}

We start by creating a native memory segment for storing 10 double values. Next, we rely on setAtIndex() to set these double values. Finally, we print them.

So, basically, we repeat the ValueLayout.JAVA_DOUBLE 10 times. When an element layout...