There is one form of array builder already in the JDK - Stream.builder(). This doesn't cover off all of the use-cases, but covers some of them (notably not the byte array case).
Thanks for pointing that out! Under-the-covers it relies on
java.util.stream.SpinedBuffer, which is built on the same type of segmented
structure I suggested. There are some differences and I need to measure some
of the performance aspects, but it is definitely aimed at the same type of
problem.
John
