Hash tables?

[rafaqz]

We never implemented these because we mostly use floating point grids with many unique values.

But, hashing can be great for

a) binary cellular automata where large areas are hashed
b) binary size-structured models where individual cells hold many species with many coohorts as binary values. See Landis Pro 6

Hashing could be pretty generic - it would need a hashing function, and a hash table. HashRule could update the hash table, which can be orders of magnitude faster than updating the grid. The main issue is it's a very limited approach in terms of adding layers of environmental heterogeneity - hash values are no longer located on the grid, instead representing many separate cells.