Removes the legacy entry points now that every caller is migrated:
FixedPatchStepper(cfg, *, context, refinements, coarse_boundary,
level_blocks, level_objects, level_jets, observe_*, explosion) and
initialize(*level_g). Deleted: positional bounds, fine_block, base_block,
fine_objects, jets, child, child_block, child_objects, child_jets,
child_rectangles_in_parent, initialize(coarse_g/fine_g/child_g),
_legacy_levels and _initial_levels. Docstring, README and docs describe
the level lists. Compatibility views (patch, fine_boundary, ...) and the
PeriodicPatchStepper alias are unchanged (separate follow-up).
Error -> rule table (legacy keyword check -> level-list rule now firing):
- several patches without fine_block/base_block -> _check_levels
'several patches require fine_block and base_block' (unchanged rule)
- base_block without fine_block -> 'a blocked level requires blocked
refined levels below it'
- nested child without all blocks -> 'three or more levels must all be
blocked' / 'a blocked level requires ...'
- fine_objects/jets with a nested child ('only on L2') -> 'bodies/Jets are
supported only on the finest level of a nested hierarchy'
- child_objects/child_jets without a nested child -> 'level_objects/
level_jets needs one entry per level'
- scalar child with several L1 patches ('scalar child requires one parent
patch') -> hierarchy 'a scalar child requires a scalar parent'
- child vs child_rectangles_in_parent mutually exclusive -> no level-list
equivalent (cannot be expressed); covered by the new explicit
RemovedLegacyAPI test: removed keywords and positional bounds raise
TypeError before any context use, initialize has only *level_g.
The InitialLevels test of the removed adapter is replaced by that test.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Additive compile-time COLLISION_MODEL == 2 branches in BlockStep,
BlockChannelStep and patch_collide repeat the uniform collide_dispatch
MRT sequence (zero forcing, omega clamp, collide_mrt_no_force). SRT
statements, including the shifted retained-delta/direct-momentum path,
are unchanged under the alternate branch. Guards accept SRT or MRT only;
TRT, LES, non-FP32, non-double-buffer and shifted dense/mixed refinement
stay rejected. Transfers, subcycling, BFL, raw ledgers, channel closures,
shifted-Jet SRT guard and PeriodicBlockStepper are untouched. Existing
MRT operator, shifted representation and fixed kinetic rates are reused.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
TRON