| # Code-ATLAS split protocol |
|
|
| ## Objective |
|
|
| Create per-language held-out code for stable next-token loss while preventing the |
| same repository, code clone, or algorithmic problem from appearing in both train |
| and evaluation. |
|
|
| ATLAS isolates, for each natural language, `min(20M tokens, 20% of available |
| tokens)` from MADLAD-400 and also evaluates on the external parallel FLORES set. |
| Code-ATLAS will preserve that loss-test token target, but randomize over grouped |
| repository components instead of individual sequences. |
|
|
| ## Required order of operations |
|
|
| 1. Freeze every upstream artifact revision and capture its source metadata. |
| 2. Normalize language labels without discarding the original label. |
| 3. Apply the license policy and quality filters. |
| 4. Compute exact content hashes across all sources. |
| 5. Form near-duplicate file clusters across all sources and languages. |
| 6. Form repository lineage components from forks, origin metadata, shared commit |
| history when available, and high file-set similarity. |
| 7. Attach task artifacts to an underlying problem family (for example HumanEval |
| task ID or CodeNet problem ID), independent of programming language. |
| 8. Construct a union graph whose edges are repository lineage, exact duplicate, |
| near duplicate, or problem-family membership. A connected component is atomic. |
| 9. Deterministically assign atomic components with frozen salt `code-atlas-v1`, |
| minimizing relative target error jointly across language token vectors. Fill |
| test quotas first and validation quotas second; never split a component. |
| 10. Run a post-split contamination scan before publishing IDs or training. |
|
|
| ## Test surfaces |
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|
| ### Held-out repository loss |
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|
| Freeze one Code-ATLAS reference tokenizer and a byte/file-span manifest before |
| splitting. For language `l`, let `U_l` be unique post-filter, post-dedup reference |
| tokens. Target `loss-test_l = min(20,000,000, 0.20 * U_l)`, matching ATLAS, and |
| target `loss-val_l = min(2,000,000, 0.10 * U_l)` for checkpoint selection. Training |
| gets the remainder. Group-boundary overshoot or undershoot is allowed and reported. |
| Require at least three independent repository-lineage components or mark that |
| language unsupported for three-way loss evaluation. |
|
|
| The frozen span manifest makes every model see identical text even if it uses a |
| different tokenizer. Report bits per UTF-8 byte or ATLAS's cited |
| vocabulary-insensitive loss, not raw tokenizer cross-entropy. Cap a single repo |
| lineage at 1% of a language loss sample and bootstrap confidence intervals by |
| repo-lineage ID. |
|
|
| ### Parallel semantic loss |
|
|
| Reserve complete problem families across languages. This is the code analogue of |
| ATLAS's external parallel test, but it must never share an underlying task with |
| `parallel_aux` training records. |
|
|
| ### Functional evaluation |
|
|
| Keep at least one executable benchmark artifact entirely untouched. Functional |
| scores are secondary diagnostics; held-out loss is the primary scaling-law |
| response. |
|
|
| For functional task corpora, create a cross-language `problem_family_id` before |
| splitting, then assign complete families 70/10/20 to task-train/dev/test. All |
| translations, solutions, tests, mutations, and same-problem judge submissions move |
| together. Bootstrap reported scores by problem family, not translated row. |
|
|
| ### Temporal loss |
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| Maintain a separately named post-cut `loss-future` panel. Its repository families |
| must first appear after a preregistered cutoff according to trusted forge/archive |
| time, with no earlier fork/clone ancestor, and must survive deduplication against |
| pre-cut data. Never average `loss-future` into the ATLAS-comparable IID test. |
|
|
| ### Scaling-law fit holdouts |
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|
| These are distinct from corpus splits. Reproduce ATLAS's fit tests: random 20% of |
| run observations, top 20% of training-token horizons, selected scales at roughly |
| 660M and 8B parameters, largest-compute observations, and unseen mixture |
| configurations. ATLAS does not state a percentage for the largest-compute holdout; |
| use its released run IDs if available or preregister a new rule and label it as a |
| Code-ATLAS clarification. `C=6ND` applies to dense decoders; otherwise report |
| measured FLOPs. |
|
|
| ## Non-negotiable leakage rules |
|
|
| - Never split by file alone. |
| - Never split translated rows of the same task across partitions. |
| - Never count repeated task translations as independent unique-code volume. |
| - Never duplicate a Nebius repository once per task row. |
| - Never allow a benchmark used for training to retain its standard benchmark name |
| in reported evaluation results. |
| - Never assign a split before global cross-source deduplication. |
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