I am trying to find the Java equivalents of the Perl regular expressions not supported by Java. These are, as listed in the Java Documentation:
\h A horizontal whitespace
\H A non horizontal whitespace
\v A vertical whitespace
\V A non vertical whitespace
\R Any Unicode linebreak sequence \u000D\u000A|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
\X Match Unicode extended grapheme cluster
However, I have no idea what any of these mean, which makes it rather challenging to recreate them.
(I think) I know what whitespace is, but I did not know there were multiple kinds of whitespace. What is the difference between horizontal, non-horizontal, vertical, and non-vertical whitespace?