Changes for version 0.003 - 2020-05-31
- Refactor the get_*_grid() code. This has resulted in signature changes, though not (I believe) to anything that was in 0.002.
Changes for version 0.002_01 - 2020-05-15
- Add methods get_active_text_grid(), get_used_text_grid(). Add bookkeeping of live cells in each row and column so the latter runs in linear time, not quadratic.
- Base grid on hash rather than array. This is faster on a large grid because I do not have to autovivify unused cells. Not surprisingly, the memory footprint is much smaller.
- Tweak change bookkeeping so that only one pass through the changes list is needed, not two.
Plays John Horton Conway's Game of Life