Cython implementation in heuristic_cy.pyx achieves ~2.55× speedup on
opponent_act_seconds (200-game eval: 59.20s → 23.24s). Original Python
implementation preserved verbatim in heuristic_py.py as the equivalence
reference. Action-sequence equivalence is verified by
test_safe_heuristic_equivalence.py against seeded game corpora.
Key implementation notes:
- File-local wraparound=True override required for negative discard
indexing; Cython global wraparound=False would segfault.
- annotation_typing=False preserves verbatim Python semantics.
- _CachedState materializes hands/expeditions/discards/deck once per
act() call — this is the dominant performance win.
Further C-array optimization of _card_value_for_me /
_card_value_for_opponent / _color_commitment / _bonus_potential is
deferred. The current 2.55× delivers most of the dense-eval future
benefit; further work is gated on actually adopting denser eval
schedules (eval_every=5, games=1000).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
