op_transform.py
python
| 1 | """Operational transformation for Muse domain operations — Phase 3. |
| 2 | |
| 3 | This module implements the commutativity rules and position-adjustment |
| 4 | transforms that allow the merge engine to reason over ``DomainOp`` trees |
| 5 | rather than file-path sets. The result is sub-file auto-merge: two agents |
| 6 | inserting notes at non-overlapping bars never produce a conflict. |
| 7 | |
| 8 | Theory |
| 9 | ------ |
| 10 | Operational Transformation (OT) is the theory behind real-time collaborative |
| 11 | editors (Google Docs, VS Code Live Share). The key insight is that two |
| 12 | *concurrent* operations — generated independently against the same base state |
| 13 | — can be applied in sequence without conflict if and only if they *commute*: |
| 14 | applying them in either order yields the same final state. |
| 15 | |
| 16 | For concurrent operations that commute, OT provides a ``transform`` function |
| 17 | that adjusts positions so that the result is identical regardless of which |
| 18 | operation is applied first. |
| 19 | |
| 20 | Public API |
| 21 | ---------- |
| 22 | - :class:`MergeOpsResult` — structured result of merging two op lists. |
| 23 | - :func:`ops_commute` — commmutativity oracle for any two ``DomainOp``\\s. |
| 24 | - :func:`transform` — position-adjusted ``(a', b')`` for commuting ops. |
| 25 | - :func:`merge_op_lists` — three-way merge at operation granularity. |
| 26 | |
| 27 | Commutativity rules (summary) |
| 28 | ------------------------------ |
| 29 | |
| 30 | ============================================= ===================================== |
| 31 | Op A Op B Commute? |
| 32 | ============================================= ===================================== |
| 33 | InsertOp(pos=i) InsertOp(pos=j) Yes — if i ≠ j or both None (unordered) |
| 34 | InsertOp(pos=i) InsertOp(pos=i) **No** — positional conflict |
| 35 | InsertOp(addr=A) DeleteOp(addr=B) Yes — if A ≠ B (different containers) |
| 36 | InsertOp(addr=A) DeleteOp(addr=A) **No** — same container |
| 37 | DeleteOp(addr=A) DeleteOp(addr=B) Yes — always (consensus delete is fine) |
| 38 | ReplaceOp(addr=A) ReplaceOp(addr=B) Yes — if A ≠ B |
| 39 | ReplaceOp(addr=A) ReplaceOp(addr=A) **No** — concurrent value conflict |
| 40 | MoveOp(from=i) MoveOp(from=j) Yes — if i ≠ j |
| 41 | MoveOp(from=i) DeleteOp(pos=i) **No** — move-delete conflict |
| 42 | PatchOp(addr=A) PatchOp(addr=B) Yes — if A ≠ B; recurse if A == B |
| 43 | ============================================= ===================================== |
| 44 | |
| 45 | Position adjustment |
| 46 | ------------------- |
| 47 | When two ``InsertOp``\\s at different positions commute, the later-applied one |
| 48 | must have its position adjusted. Concretely, if *a* inserts at position *i* |
| 49 | and *b* inserts at position *j* with *i < j*: |
| 50 | |
| 51 | - Applying *a* first shifts every element at position ≥ i by one; so *b* |
| 52 | must be adjusted to *j + 1*. |
| 53 | - Applying *b* first does not affect positions < j; so *a* stays at *i*. |
| 54 | |
| 55 | For *merge_op_lists*, positions are adjusted via the **counting formula**: for |
| 56 | each InsertOp in one side's exclusive additions, add the count of the other |
| 57 | side's InsertOps that have position ≤ this op's position (on the same |
| 58 | address). This is correct for any number of concurrent insertions and avoids |
| 59 | the cascading adjustment errors that arise from naive sequential pairwise OT. |
| 60 | |
| 61 | Synchronous guarantee |
| 62 | --------------------- |
| 63 | All functions are synchronous, pure, and allocation-bounded — no I/O, no |
| 64 | async, no external state. |
| 65 | """ |
| 66 | from __future__ import annotations |
| 67 | |
| 68 | import logging |
| 69 | from dataclasses import dataclass, field |
| 70 | |
| 71 | from muse.domain import ( |
| 72 | DeleteOp, |
| 73 | DomainOp, |
| 74 | InsertOp, |
| 75 | MoveOp, |
| 76 | PatchOp, |
| 77 | ReplaceOp, |
| 78 | StructuredDelta, |
| 79 | ) |
| 80 | |
| 81 | logger = logging.getLogger(__name__) |
| 82 | |
| 83 | |
| 84 | # --------------------------------------------------------------------------- |
| 85 | # Result type |
| 86 | # --------------------------------------------------------------------------- |
| 87 | |
| 88 | |
| 89 | @dataclass |
| 90 | class MergeOpsResult: |
| 91 | """Result of a three-way operation-level merge. |
| 92 | |
| 93 | ``merged_ops`` contains the operations from both sides that can be applied |
| 94 | to the common ancestor to produce the merged state. Positions in any |
| 95 | ``InsertOp`` entries have been adjusted so that the ops can be applied in |
| 96 | ascending position order to produce a deterministic result. |
| 97 | |
| 98 | ``conflict_ops`` contains pairs ``(our_op, their_op)`` where the two |
| 99 | operations cannot be auto-merged. Each pair must be resolved manually |
| 100 | (or via ``.museattributes`` strategy) before the merge can complete. |
| 101 | |
| 102 | ``is_clean`` is ``True`` when ``conflict_ops`` is empty. |
| 103 | """ |
| 104 | |
| 105 | merged_ops: list[DomainOp] = field(default_factory=list) |
| 106 | conflict_ops: list[tuple[DomainOp, DomainOp]] = field(default_factory=list) |
| 107 | |
| 108 | @property |
| 109 | def is_clean(self) -> bool: |
| 110 | """``True`` when no conflicting operation pairs were found.""" |
| 111 | return len(self.conflict_ops) == 0 |
| 112 | |
| 113 | |
| 114 | # --------------------------------------------------------------------------- |
| 115 | # Internal helpers |
| 116 | # --------------------------------------------------------------------------- |
| 117 | |
| 118 | |
| 119 | def _op_key(op: DomainOp) -> tuple[str, ...]: |
| 120 | """Return a hashable key uniquely identifying *op* for set membership tests. |
| 121 | |
| 122 | The key captures all semantically significant fields so that two ops with |
| 123 | identical effect produce the same key. This is used to detect consensus |
| 124 | operations (both sides added the same op independently). |
| 125 | """ |
| 126 | if op["op"] == "insert": |
| 127 | return ("insert", op["address"], str(op["position"]), op["content_id"]) |
| 128 | if op["op"] == "delete": |
| 129 | return ("delete", op["address"], str(op["position"]), op["content_id"]) |
| 130 | if op["op"] == "move": |
| 131 | return ( |
| 132 | "move", |
| 133 | op["address"], |
| 134 | str(op["from_position"]), |
| 135 | str(op["to_position"]), |
| 136 | op["content_id"], |
| 137 | ) |
| 138 | if op["op"] == "replace": |
| 139 | return ( |
| 140 | "replace", |
| 141 | op["address"], |
| 142 | str(op["position"]), |
| 143 | op["old_content_id"], |
| 144 | op["new_content_id"], |
| 145 | ) |
| 146 | # PatchOp — key on address and child_domain; child_ops are not hashed for |
| 147 | # performance reasons. Two patch ops on the same container are treated as |
| 148 | # the same "slot" for conflict detection purposes. |
| 149 | return ("patch", op["address"], op["child_domain"]) |
| 150 | |
| 151 | |
| 152 | # --------------------------------------------------------------------------- |
| 153 | # Commutativity oracle |
| 154 | # --------------------------------------------------------------------------- |
| 155 | |
| 156 | |
| 157 | def ops_commute(a: DomainOp, b: DomainOp) -> bool: |
| 158 | """Return ``True`` if operations *a* and *b* commute (are auto-mergeable). |
| 159 | |
| 160 | Two operations commute when applying them in either order produces the |
| 161 | same final state. This function implements the commutativity rules table |
| 162 | from the Phase 3 spec for all 25 op-kind pairs. |
| 163 | |
| 164 | For ``PatchOp`` at the same address, commmutativity is determined |
| 165 | recursively by checking all child-op pairs. |
| 166 | |
| 167 | Args: |
| 168 | a: First domain operation. |
| 169 | b: Second domain operation. |
| 170 | |
| 171 | Returns: |
| 172 | ``True`` if the two operations can be safely auto-merged. |
| 173 | """ |
| 174 | # ------------------------------------------------------------------ |
| 175 | # InsertOp + * |
| 176 | # ------------------------------------------------------------------ |
| 177 | if a["op"] == "insert": |
| 178 | if b["op"] == "insert": |
| 179 | # Different containers always commute — they are completely independent. |
| 180 | if a["address"] != b["address"]: |
| 181 | return True |
| 182 | a_pos, b_pos = a["position"], b["position"] |
| 183 | # Unordered collections (position=None) always commute. |
| 184 | if a_pos is None or b_pos is None: |
| 185 | return True |
| 186 | # Ordered sequences within the same container: conflict only at equal positions. |
| 187 | return a_pos != b_pos |
| 188 | if b["op"] == "delete": |
| 189 | # Conservative: inserts and deletes at the same container conflict. |
| 190 | return a["address"] != b["address"] |
| 191 | if b["op"] == "move": |
| 192 | return a["address"] != b["address"] |
| 193 | if b["op"] == "replace": |
| 194 | return a["address"] != b["address"] |
| 195 | # b is PatchOp (exhaustion of DeleteOp | MoveOp | ReplaceOp | PatchOp) |
| 196 | return a["address"] != b["address"] |
| 197 | |
| 198 | # ------------------------------------------------------------------ |
| 199 | # DeleteOp + * |
| 200 | # ------------------------------------------------------------------ |
| 201 | if a["op"] == "delete": |
| 202 | if b["op"] == "insert": |
| 203 | return a["address"] != b["address"] |
| 204 | if b["op"] == "delete": |
| 205 | # Consensus delete (same or different address) always commutes. |
| 206 | # Two branches that both removed the same element produce the same |
| 207 | # result: the element is absent. |
| 208 | return True |
| 209 | if b["op"] == "move": |
| 210 | # Conflict if the delete's position matches the move's source. |
| 211 | a_pos = a["position"] |
| 212 | if a_pos is None: |
| 213 | return True # unordered collection: no positional conflict |
| 214 | return a_pos != b["from_position"] |
| 215 | if b["op"] == "replace": |
| 216 | return a["address"] != b["address"] |
| 217 | # b is PatchOp |
| 218 | return a["address"] != b["address"] |
| 219 | |
| 220 | # ------------------------------------------------------------------ |
| 221 | # MoveOp + * |
| 222 | # ------------------------------------------------------------------ |
| 223 | if a["op"] == "move": |
| 224 | if b["op"] == "insert": |
| 225 | return a["address"] != b["address"] |
| 226 | if b["op"] == "delete": |
| 227 | b_pos = b["position"] |
| 228 | if b_pos is None: |
| 229 | return True |
| 230 | return a["from_position"] != b_pos |
| 231 | if b["op"] == "move": |
| 232 | # Two moves from different source positions commute. |
| 233 | return a["from_position"] != b["from_position"] |
| 234 | if b["op"] == "replace": |
| 235 | return a["address"] != b["address"] |
| 236 | # b is PatchOp |
| 237 | return a["address"] != b["address"] |
| 238 | |
| 239 | # ------------------------------------------------------------------ |
| 240 | # ReplaceOp + * |
| 241 | # ------------------------------------------------------------------ |
| 242 | if a["op"] == "replace": |
| 243 | if b["op"] == "insert": |
| 244 | return a["address"] != b["address"] |
| 245 | if b["op"] == "delete": |
| 246 | return a["address"] != b["address"] |
| 247 | if b["op"] == "move": |
| 248 | return a["address"] != b["address"] |
| 249 | if b["op"] == "replace": |
| 250 | # Two replaces at the same address conflict (concurrent value change). |
| 251 | return a["address"] != b["address"] |
| 252 | # b is PatchOp |
| 253 | return a["address"] != b["address"] |
| 254 | |
| 255 | # ------------------------------------------------------------------ |
| 256 | # PatchOp + * (a["op"] == "patch" after the four checks above) |
| 257 | # ------------------------------------------------------------------ |
| 258 | if b["op"] == "insert": |
| 259 | return a["address"] != b["address"] |
| 260 | if b["op"] == "delete": |
| 261 | return a["address"] != b["address"] |
| 262 | if b["op"] == "move": |
| 263 | return a["address"] != b["address"] |
| 264 | if b["op"] == "replace": |
| 265 | return a["address"] != b["address"] |
| 266 | # b is PatchOp |
| 267 | if a["address"] != b["address"]: |
| 268 | return True |
| 269 | # Same address: recurse into child ops — all child pairs must commute. |
| 270 | for child_a in a["child_ops"]: |
| 271 | for child_b in b["child_ops"]: |
| 272 | if not ops_commute(child_a, child_b): |
| 273 | return False |
| 274 | return True |
| 275 | |
| 276 | |
| 277 | # --------------------------------------------------------------------------- |
| 278 | # OT transform |
| 279 | # --------------------------------------------------------------------------- |
| 280 | |
| 281 | |
| 282 | def transform(a: DomainOp, b: DomainOp) -> tuple[DomainOp, DomainOp]: |
| 283 | """Return ``(a', b')`` such that ``apply(apply(base, a), b') == apply(apply(base, b), a')``. |
| 284 | |
| 285 | This is the core OT transform function. It should only be called when |
| 286 | :func:`ops_commute` has confirmed that *a* and *b* commute. For all |
| 287 | commuting pairs except ordered InsertOp+InsertOp, the identity transform |
| 288 | is returned — the operations do not interfere with each other's positions. |
| 289 | |
| 290 | For the InsertOp+InsertOp case with integer positions (the most common |
| 291 | case in practice), positions are adjusted so the diamond property holds: |
| 292 | the same final sequence is produced regardless of application order. |
| 293 | |
| 294 | Args: |
| 295 | a: First domain operation. |
| 296 | b: Second domain operation (must commute with *a*). |
| 297 | |
| 298 | Returns: |
| 299 | A tuple ``(a', b')`` where: |
| 300 | |
| 301 | - *a'* is the version of *a* to apply when *b* has already been applied. |
| 302 | - *b'* is the version of *b* to apply when *a* has already been applied. |
| 303 | """ |
| 304 | if a["op"] == "insert" and b["op"] == "insert": |
| 305 | a_pos, b_pos = a["position"], b["position"] |
| 306 | if a_pos is not None and b_pos is not None and a_pos != b_pos: |
| 307 | if a_pos < b_pos: |
| 308 | # a inserts before b's original position → b shifts up by 1. |
| 309 | b_prime = InsertOp( |
| 310 | op="insert", |
| 311 | address=b["address"], |
| 312 | position=b_pos + 1, |
| 313 | content_id=b["content_id"], |
| 314 | content_summary=b["content_summary"], |
| 315 | ) |
| 316 | return a, b_prime |
| 317 | else: |
| 318 | # b inserts before a's original position → a shifts up by 1. |
| 319 | a_prime = InsertOp( |
| 320 | op="insert", |
| 321 | address=a["address"], |
| 322 | position=a_pos + 1, |
| 323 | content_id=a["content_id"], |
| 324 | content_summary=a["content_summary"], |
| 325 | ) |
| 326 | return a_prime, b |
| 327 | |
| 328 | # All other commuting pairs: identity transform. |
| 329 | return a, b |
| 330 | |
| 331 | |
| 332 | # --------------------------------------------------------------------------- |
| 333 | # Three-way merge at operation granularity |
| 334 | # --------------------------------------------------------------------------- |
| 335 | |
| 336 | |
| 337 | def _adjust_insert_positions( |
| 338 | ops: list[DomainOp], |
| 339 | other_ops: list[DomainOp], |
| 340 | ) -> list[DomainOp]: |
| 341 | """Adjust ``InsertOp`` positions in *ops* to account for *other_ops*. |
| 342 | |
| 343 | For each ``InsertOp`` with a non-``None`` position in *ops*, the adjusted |
| 344 | position is ``original_position + count`` where ``count`` is the number of |
| 345 | ``InsertOp``\\s in *other_ops* that share the same ``address`` and have |
| 346 | ``position ≤ original_position``. |
| 347 | |
| 348 | This implements the *counting formula* for multi-op position adjustment. |
| 349 | It is correct for any number of concurrent insertions on each side, |
| 350 | producing the same final sequence regardless of application order. |
| 351 | |
| 352 | Non-``InsertOp`` entries and unordered inserts (``position=None``) pass |
| 353 | through unchanged. |
| 354 | |
| 355 | Args: |
| 356 | ops: The list of ops whose positions need adjustment. |
| 357 | other_ops: The concurrent operations from the other branch. |
| 358 | |
| 359 | Returns: |
| 360 | A new list with adjusted ``InsertOp``\\s; all other entries are copied |
| 361 | unchanged. |
| 362 | """ |
| 363 | # Collect other-side InsertOp positions, grouped by address. |
| 364 | other_by_addr: dict[str, list[int]] = {} |
| 365 | for op in other_ops: |
| 366 | if op["op"] == "insert" and op["position"] is not None: |
| 367 | addr = op["address"] |
| 368 | if addr not in other_by_addr: |
| 369 | other_by_addr[addr] = [] |
| 370 | other_by_addr[addr].append(op["position"]) |
| 371 | |
| 372 | result: list[DomainOp] = [] |
| 373 | for op in ops: |
| 374 | if op["op"] == "insert" and op["position"] is not None: |
| 375 | addr = op["address"] |
| 376 | pos = op["position"] |
| 377 | others = other_by_addr.get(addr, []) |
| 378 | shift = sum(1 for p in others if p <= pos) |
| 379 | if shift: |
| 380 | result.append( |
| 381 | InsertOp( |
| 382 | op="insert", |
| 383 | address=addr, |
| 384 | position=pos + shift, |
| 385 | content_id=op["content_id"], |
| 386 | content_summary=op["content_summary"], |
| 387 | ) |
| 388 | ) |
| 389 | else: |
| 390 | result.append(op) |
| 391 | else: |
| 392 | result.append(op) |
| 393 | |
| 394 | return result |
| 395 | |
| 396 | |
| 397 | def merge_op_lists( |
| 398 | base_ops: list[DomainOp], |
| 399 | ours_ops: list[DomainOp], |
| 400 | theirs_ops: list[DomainOp], |
| 401 | ) -> MergeOpsResult: |
| 402 | """Three-way merge at operation granularity. |
| 403 | |
| 404 | Implements the standard three-way merge algorithm applied to typed domain |
| 405 | operations rather than file-path sets. The inputs represent: |
| 406 | |
| 407 | - *base_ops*: operations present in the common ancestor. |
| 408 | - *ours_ops*: operations present on our branch (superset of base for |
| 409 | kept ops, plus our new additions). |
| 410 | - *theirs_ops*: operations present on their branch (same structure). |
| 411 | |
| 412 | Algorithm |
| 413 | --------- |
| 414 | 1. **Kept from base** — ops in base that both sides retained are included |
| 415 | unchanged. |
| 416 | 2. **Consensus additions** — ops added independently by both sides (same |
| 417 | key) are included exactly once (idempotent). |
| 418 | 3. **Exclusive additions** — ops added by only one side enter the |
| 419 | commmutativity check: |
| 420 | |
| 421 | - Any pair (ours_exclusive, theirs_exclusive) where |
| 422 | :func:`ops_commute` returns ``False`` is recorded as a conflict. |
| 423 | - Exclusive additions not involved in any conflict are included in |
| 424 | ``merged_ops``, with ``InsertOp`` positions adjusted via |
| 425 | :func:`_adjust_insert_positions`. |
| 426 | |
| 427 | Position adjustment note |
| 428 | ------------------------ |
| 429 | The adjusted ``InsertOp`` positions in ``merged_ops`` are *absolute |
| 430 | positions in the final merged sequence* — meaning they already account for |
| 431 | all insertions from both sides. Callers applying the merged ops to the |
| 432 | base state should apply ``InsertOp``\\s in ascending position order to |
| 433 | obtain the correct final sequence. |
| 434 | |
| 435 | Args: |
| 436 | base_ops: Operations in the common ancestor delta. |
| 437 | ours_ops: Operations on our branch. |
| 438 | theirs_ops: Operations on their branch. |
| 439 | |
| 440 | Returns: |
| 441 | A :class:`MergeOpsResult` with merged and conflicting op lists. |
| 442 | """ |
| 443 | base_key_set = {_op_key(op) for op in base_ops} |
| 444 | ours_key_set = {_op_key(op) for op in ours_ops} |
| 445 | theirs_key_set = {_op_key(op) for op in theirs_ops} |
| 446 | |
| 447 | # 1. Ops both sides kept from the base. |
| 448 | kept: list[DomainOp] = [ |
| 449 | op |
| 450 | for op in base_ops |
| 451 | if _op_key(op) in ours_key_set and _op_key(op) in theirs_key_set |
| 452 | ] |
| 453 | |
| 454 | # 2. New ops — not present in base. |
| 455 | ours_new = [op for op in ours_ops if _op_key(op) not in base_key_set] |
| 456 | theirs_new = [op for op in theirs_ops if _op_key(op) not in base_key_set] |
| 457 | |
| 458 | ours_new_keys = {_op_key(op) for op in ours_new} |
| 459 | theirs_new_keys = {_op_key(op) for op in theirs_new} |
| 460 | consensus_keys = ours_new_keys & theirs_new_keys |
| 461 | |
| 462 | # Consensus additions: both sides added the same op → include once. |
| 463 | consensus: list[DomainOp] = [ |
| 464 | op for op in ours_new if _op_key(op) in consensus_keys |
| 465 | ] |
| 466 | |
| 467 | # 3. Each side's exclusive new additions. |
| 468 | ours_exclusive = [op for op in ours_new if _op_key(op) not in consensus_keys] |
| 469 | theirs_exclusive = [op for op in theirs_new if _op_key(op) not in consensus_keys] |
| 470 | |
| 471 | # Conflict detection: any pair from both sides that does not commute. |
| 472 | conflict_ops: list[tuple[DomainOp, DomainOp]] = [] |
| 473 | conflicting_ours_keys: set[tuple[str, ...]] = set() |
| 474 | conflicting_theirs_keys: set[tuple[str, ...]] = set() |
| 475 | |
| 476 | for our_op in ours_exclusive: |
| 477 | for their_op in theirs_exclusive: |
| 478 | if not ops_commute(our_op, their_op): |
| 479 | conflict_ops.append((our_op, their_op)) |
| 480 | conflicting_ours_keys.add(_op_key(our_op)) |
| 481 | conflicting_theirs_keys.add(_op_key(their_op)) |
| 482 | |
| 483 | # 4. Clean ops: not involved in any conflict. |
| 484 | clean_ours = [ |
| 485 | op for op in ours_exclusive if _op_key(op) not in conflicting_ours_keys |
| 486 | ] |
| 487 | clean_theirs = [ |
| 488 | op for op in theirs_exclusive if _op_key(op) not in conflicting_theirs_keys |
| 489 | ] |
| 490 | |
| 491 | # 5. Position adjustment using the counting formula. |
| 492 | clean_ours_adjusted = _adjust_insert_positions(clean_ours, clean_theirs) |
| 493 | clean_theirs_adjusted = _adjust_insert_positions(clean_theirs, clean_ours) |
| 494 | |
| 495 | merged_ops: list[DomainOp] = ( |
| 496 | list(kept) + list(consensus) + clean_ours_adjusted + clean_theirs_adjusted |
| 497 | ) |
| 498 | |
| 499 | logger.debug( |
| 500 | "merge_op_lists: kept=%d consensus=%d ours=%d theirs=%d conflicts=%d", |
| 501 | len(kept), |
| 502 | len(consensus), |
| 503 | len(clean_ours_adjusted), |
| 504 | len(clean_theirs_adjusted), |
| 505 | len(conflict_ops), |
| 506 | ) |
| 507 | |
| 508 | return MergeOpsResult(merged_ops=merged_ops, conflict_ops=conflict_ops) |
| 509 | |
| 510 | |
| 511 | def merge_structured( |
| 512 | base_delta: StructuredDelta, |
| 513 | ours_delta: StructuredDelta, |
| 514 | theirs_delta: StructuredDelta, |
| 515 | ) -> MergeOpsResult: |
| 516 | """Merge two structured deltas against a common base delta. |
| 517 | |
| 518 | A convenience wrapper over :func:`merge_op_lists` that accepts |
| 519 | :class:`~muse.domain.StructuredDelta` objects directly. |
| 520 | |
| 521 | Args: |
| 522 | base_delta: Delta representing the common ancestor's operations. |
| 523 | ours_delta: Delta produced by our branch. |
| 524 | theirs_delta: Delta produced by their branch. |
| 525 | |
| 526 | Returns: |
| 527 | A :class:`MergeOpsResult` describing the merged and conflicting ops. |
| 528 | """ |
| 529 | return merge_op_lists( |
| 530 | base_delta["ops"], |
| 531 | ours_delta["ops"], |
| 532 | theirs_delta["ops"], |
| 533 | ) |