- String.getChars copies into a char-array; String. builds from a char[]
(whole or offset/count slice); subSequence returns the substring.
- str of a StringBuilder returns its content (was the opaque host object;
.toString already worked).
- Appendable.append gains the 3-arg subsequence form append(csq,start,end)
on StringBuilder/StringWriter/file/port writers.
- reader combines a \uXXXX surrogate pair into the one Unicode scalar
(😃) instead of crashing on the lone high surrogate; a stray surrogate
maps to U+FFFD. (A high-plane char re-escaped as \uXXXXX stays the
irreducible UTF-16/scalar divergence.)
- TimeZone/getDefault.
These let clojure.data.json read and write JSON; its own suite goes from
not loading to 97/133 assertions passing (remainder: per-type writer
dispatch for uuid/bigdec/date, EOFException, niche date interop).