FYC: 7197183 : Provide CharSequence.subSequenceView which allows for sub-sequence views of character sequences.

[Peter Levart]

Hi Mike,

Just a warning that CharSubSequenceView is a public class, which is not
what you wanted it to be, I think, since its constructors are pkg private.

IntSupplier trick is nice, but it makes the wrapper object heavier. If the
purpose was to support tracking source sequence length with some optional
constant offset (I.e. source.length() - n) then an overloaded method could
do the trick.
Did you have any other use case in mind?

Regards, Peter