{"abstract":"The operation returns a result or retained state that violates this contract: Replace the half-open positional slice with all supplied elements, allowing length changes.","category":"Container mutation","checks":4,"contract":"Replace the half-open positional slice with all supplied elements, allowing length changes. Inputs are the finite Python values shown by the executable fixtures; no concurrent execution is assumed.","contract_signature":"x, y=None","evaluation_group":"model-d1d05c4d293eaede","failed_approach":"An empty insertion range preserves the old selected content.","family":"xr-list-splice-replaces-range","id":"FA-4346","implementations":{"attempt":{"sha256":"202f4d74f8f1186d77abd9e61b3d8ac9a38175b1df813e135d346d64f1ba666e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x, y=None):\n    a=list(x); a[y[0]:y[0]]=y[2]; return a\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('exclusive end', solve(['a', 'b', 'c'], [1, 2, ['d']]), ['a', 'd', 'c'])\ncheck('insert empty range', solve(['a', 'b'], [1, 1, ['d']]), ['a', 'd', 'b'])\ncheck('delete range', solve(['a', 'b'], [0, 2, []]), [])\ncheck('empty splice', solve([], [0, 0, ['d']]), ['d'])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"3781246151800e9bea7f5aa97c9523c7e24336675a34306dfa4667c99938c64e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x, y=None):\n    a=list(x); a[y[0]:y[1]+1]=y[2]; return a\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('exclusive end', solve(['a', 'b', 'c'], [1, 2, ['d']]), ['a', 'd', 'c'])\ncheck('insert empty range', solve(['a', 'b'], [1, 1, ['d']]), ['a', 'd', 'b'])\ncheck('delete range', solve(['a', 'b'], [0, 2, []]), [])\ncheck('empty splice', solve([], [0, 0, ['d']]), ['d'])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":" This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xr-list-splice-replaces-range","generated_at":"2026-09-29T14:37:38.293731+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A controlled local-runtime regression for collection APIs, language semantics, or ownership wrappers. Fixtures include boundary and interaction cases.","root_cause":"An inclusive end removes the first unselected suffix element.","sha256":"187f75078ad6dfd2cf9304e35408f8395c8b97a0dca54b19339b692c3a3719c8","title":"List splice replaces range · case 01","variant":1,"variant_policy":"Five execution reruns of a fixed adversarial fixture suite; variant number does not alter semantic inputs.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":37.412,"exit_code":1,"observations":[{"actual":["a","d","b","c"],"check":"exclusive end","expected":["a","d","c"],"passed":false},{"actual":["a","d","b"],"check":"insert empty range","expected":["a","d","b"],"passed":true},{"actual":["a","b"],"check":"delete range","expected":[],"passed":false},{"actual":["d"],"check":"empty splice","expected":["d"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"exclusive end\", \"actual\": [\"a\", \"d\", \"b\", \"c\"], \"expected\": [\"a\", \"d\", \"c\"], \"passed\": false}, {\"check\": \"insert empty range\", \"actual\": [\"a\", \"d\", \"b\"], \"expected\": [\"a\", \"d\", \"b\"], \"passed\": true}, {\"check\": \"delete range\", \"actual\": [\"a\", \"b\"], \"expected\": [], \"passed\": false}, {\"check\": \"empty splice\", \"actual\": [\"d\"], \"expected\": [\"d\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":110.408,"exit_code":1,"observations":[{"actual":["a","d"],"check":"exclusive end","expected":["a","d","c"],"passed":false},{"actual":["a","d"],"check":"insert empty range","expected":["a","d","b"],"passed":false},{"actual":[],"check":"delete range","expected":[],"passed":true},{"actual":["d"],"check":"empty splice","expected":["d"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"exclusive end\", \"actual\": [\"a\", \"d\"], \"expected\": [\"a\", \"d\", \"c\"], \"passed\": false}, {\"check\": \"insert empty range\", \"actual\": [\"a\", \"d\"], \"expected\": [\"a\", \"d\", \"b\"], \"passed\": false}, {\"check\": \"delete range\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty splice\", \"actual\": [\"d\"], \"expected\": [\"d\"], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}