the combo is more flexible than if the two groups were split apart into two classes, because this lets you switch back and forth as needed… I’ve used this when I wanted to write a quick and dirty FIX protocol parser

https://en.m.wikipedia.org/wiki/Financial_Information_eXchange

First you can read the hard coded string (no need for tokens here)

8=FIX.4.2 | 9=

which gets right to the point where you need an integer, so you can use nextShort (with the proper delimiter) and then you can get the rest of the message(again no need for tokens)

this barely qualifies as a parser; we have not even attempted to understand the message, but at least it’s good enough to break up a stream into messages at the proper message boundaries.

Thanks a lot. You and your talks on topics related to Java is really awesome. retainAll() was super nice as well which serves as A ∩ B
Thanks again.

Hi, thanks for watching my old talk! I guess I never uploaded that file. I’ve done so now. Here’s a link to that file. (I’ve also updated the post to include the link.)

https://stuartmarks.files.wordpress.com/2019/09/ccc.jshell.txt

Right, the idea of SequencedCollection elements having successors and predecessors is mostly for definitional purposes. There aren’t any such operations in the APIs, as you noted.

You might look at NavigableSet, which has higher(E) and lower(E) methods that let you find the adjacent elements. NavigableMap has similar methods for finding adjacent keys and entries, given a key. Using these APIs you can “iterate” through a NavigableSet or NavigableMap without using an explicit Iterator object.