Immutable Testing

[nsmryan]

Performance testing with immutable structures and single traversal of data.

Either find a way to combine mutation and crossover, or have each operation output a description of what it wants to do (dense update, sparse update, move block) and treat the whole population as a single tree.
Specialize for a GA at first, generate the movements desired, and resolve what needs to happen. Then just go through the population once, doing O(n) splits taking O(ln(n)) time and joins taking O(ln(n)) time.
Do performance testing against the other RGEP implementations to see if the cache behavior helps enough to make this worth it.