Refactor benchmark
JSON tester sanity check
Comparisons
Reify ItemSets (prep for optimization)
Some basic memoization
Merge branch 'performance' into perf-unstable
Benchmarking suite
Perf improvements
Checkpoint: multithreaded test (not passing)
Thread-safety
Renaming some things
Checkpoint: da-test
Checkpoint: nda-test
Checkpoint: most cases work
Checkpoint: partials
Checkpoint: Null results
Checkpoint: eager-advance
Checkpoint: Most tests passing
Earley automaton with empty rule
Performance: Deep unification of stacks