{"abstract":"A structured table violates the declared record or column contract.","category":"Delimited text","checks":11,"contract":"Parse comma fields index=value into a fixed-width dense row. Indexes are unsigned decimal integers, zero based, strictly increasing and less than width; equal indexes reject. Missing positions remain null. Values may contain equals; empty values are retained.","evaluation_group":"s3-delimited-text-sparse-indexed-row","failed_approach":"A numeric sentinel also invents a supplied value.","family":"s3-delimited-text-sparse-indexed-row-missing-value","id":"FA-47606","implementations":{"attempt":{"sha256":"0a984f9a4a4b461158987f61fbfd44b9aca1b84533be95b9b749bdcc3836bcf2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    out = [0] * data['width']\n    last = -1\n    for cell in data['row'].split(',') if data['row'] else []:\n        parts = cell.split('=', 1)\n        if len(parts) != 2: return None\n        index, value = parts\n        if not index.isascii() or not index.isdecimal(): return None\n        index = int(index)\n        if index <= last or index >= data['width']: return None\n        out[index] = value\n        last = index\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('gaps', solve(_vary({'width': 4, 'row': '0=@,2=z'})), _vary(['@', None, 'z', None]))\ncheck('equals value', solve(_vary({'width': 2, 'row': '1=a=b'})), _vary([None, 'a=b']))\ncheck('empty value', solve(_vary({'width': 2, 'row': '0='})), _vary(['', None]))\ncheck('duplicate', solve(_vary({'width': 2, 'row': '0=x,0=y'})), _vary(None))\ncheck('decreasing', solve(_vary({'width': 3, 'row': '2=x,1=y'})), _vary(None))\ncheck('out of bounds', solve(_vary({'width': 2, 'row': '2=x'})), _vary(None))\ncheck('negative', solve(_vary({'width': 2, 'row': '-1=x'})), _vary(None))\ncheck('Unicode digit', solve(_vary({'width': 2, 'row': '١=x'})), _vary(None))\ncheck('empty row', solve(_vary({'width': 3, 'row': ''})), _vary([None, None, None]))\ncheck('last slot', solve(_vary({'width': 2, 'row': '1=@'})), _vary([None, '@']))\ncheck('malformed', solve(_vary({'width': 2, 'row': '0'})), _vary(None))\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":"ff6e3ccdd88768e72fd99bba18f118e222e669a06045fa2c1054ba1a635515b4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    out = [''] * data['width']\n    last = -1\n    for cell in data['row'].split(',') if data['row'] else []:\n        parts = cell.split('=', 1)\n        if len(parts) != 2: return None\n        index, value = parts\n        if not index.isascii() or not index.isdecimal(): return None\n        index = int(index)\n        if index <= last or index >= data['width']: return None\n        out[index] = value\n        last = index\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('gaps', solve(_vary({'width': 4, 'row': '0=@,2=z'})), _vary(['@', None, 'z', None]))\ncheck('equals value', solve(_vary({'width': 2, 'row': '1=a=b'})), _vary([None, 'a=b']))\ncheck('empty value', solve(_vary({'width': 2, 'row': '0='})), _vary(['', None]))\ncheck('duplicate', solve(_vary({'width': 2, 'row': '0=x,0=y'})), _vary(None))\ncheck('decreasing', solve(_vary({'width': 3, 'row': '2=x,1=y'})), _vary(None))\ncheck('out of bounds', solve(_vary({'width': 2, 'row': '2=x'})), _vary(None))\ncheck('negative', solve(_vary({'width': 2, 'row': '-1=x'})), _vary(None))\ncheck('Unicode digit', solve(_vary({'width': 2, 'row': '١=x'})), _vary(None))\ncheck('empty row', solve(_vary({'width': 3, 'row': ''})), _vary([None, None, None]))\ncheck('last slot', solve(_vary({'width': 2, 'row': '1=@'})), _vary([None, '@']))\ncheck('malformed', solve(_vary({'width': 2, 'row': '0'})), _vary(None))\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"},"fixed":{"sha256":"ebde7d9d18958d4e1cfacab840730be2957c345cf185ef26b808ebe1c3c3e9f0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    out = [None] * data['width']\n    last = -1\n    for cell in data['row'].split(',') if data['row'] else []:\n        parts = cell.split('=', 1)\n        if len(parts) != 2: return None\n        index, value = parts\n        if not index.isascii() or not index.isdecimal(): return None\n        index = int(index)\n        if index <= last or index >= data['width']: return None\n        out[index] = value\n        last = index\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('gaps', solve(_vary({'width': 4, 'row': '0=@,2=z'})), _vary(['@', None, 'z', None]))\ncheck('equals value', solve(_vary({'width': 2, 'row': '1=a=b'})), _vary([None, 'a=b']))\ncheck('empty value', solve(_vary({'width': 2, 'row': '0='})), _vary(['', None]))\ncheck('duplicate', solve(_vary({'width': 2, 'row': '0=x,0=y'})), _vary(None))\ncheck('decreasing', solve(_vary({'width': 3, 'row': '2=x,1=y'})), _vary(None))\ncheck('out of bounds', solve(_vary({'width': 2, 'row': '2=x'})), _vary(None))\ncheck('negative', solve(_vary({'width': 2, 'row': '-1=x'})), _vary(None))\ncheck('Unicode digit', solve(_vary({'width': 2, 'row': '١=x'})), _vary(None))\ncheck('empty row', solve(_vary({'width': 3, 'row': ''})), _vary([None, None, None]))\ncheck('last slot', solve(_vary({'width': 2, 'row': '1=@'})), _vary([None, '@']))\ncheck('malformed', solve(_vary({'width': 2, 'row': '0'})), _vary(None))\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":"Deterministic bounded in-memory model. No claim of complete CSV or external format conformance. 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":"s3-delimited-text-sparse-indexed-row-missing-value","generated_at":"2026-09-29T14:44:43.139267+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Delimited interchange needs explicit framing, schema and field semantics at ingestion and emission boundaries.","repair":"Preserve the named invariant at the faulty decision: out = [None] * data['width']","root_cause":"The fill value conflates an omitted column with an explicit empty string.","sha256":"5aef09d1d14cba101b2bcf39d9f3c34135bef97140ed629d4a46e9a50c884c84","title":"Unspecified sparse cells become empty strings · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.548,"exit_code":1,"observations":[{"actual":["cell",0,"z",0],"check":"gaps","expected":["cell",null,"z",null],"passed":false},{"actual":[0,"a=b"],"check":"equals value","expected":[null,"a=b"],"passed":false},{"actual":["",0],"check":"empty value","expected":["",null],"passed":false},{"actual":null,"check":"duplicate","expected":null,"passed":true},{"actual":null,"check":"decreasing","expected":null,"passed":true},{"actual":null,"check":"out of bounds","expected":null,"passed":true},{"actual":null,"check":"negative","expected":null,"passed":true},{"actual":null,"check":"Unicode digit","expected":null,"passed":true},{"actual":[0,0,0],"check":"empty row","expected":[null,null,null],"passed":false},{"actual":[0,"cell"],"check":"last slot","expected":[null,"cell"],"passed":false},{"actual":null,"check":"malformed","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"gaps\", \"actual\": [\"cell\", 0, \"z\", 0], \"expected\": [\"cell\", null, \"z\", null], \"passed\": false}, {\"check\": \"equals value\", \"actual\": [0, \"a=b\"], \"expected\": [null, \"a=b\"], \"passed\": false}, {\"check\": \"empty value\", \"actual\": [\"\", 0], \"expected\": [\"\", null], \"passed\": false}, {\"check\": \"duplicate\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"decreasing\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"out of bounds\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"negative\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"Unicode digit\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty row\", \"actual\": [0, 0, 0], \"expected\": [null, null, null], \"passed\": false}, {\"check\": \"last slot\", \"actual\": [0, \"cell\"], \"expected\": [null, \"cell\"], \"passed\": false}, {\"check\": \"malformed\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.343,"exit_code":1,"observations":[{"actual":["cell","","z",""],"check":"gaps","expected":["cell",null,"z",null],"passed":false},{"actual":["","a=b"],"check":"equals value","expected":[null,"a=b"],"passed":false},{"actual":["",""],"check":"empty value","expected":["",null],"passed":false},{"actual":null,"check":"duplicate","expected":null,"passed":true},{"actual":null,"check":"decreasing","expected":null,"passed":true},{"actual":null,"check":"out of bounds","expected":null,"passed":true},{"actual":null,"check":"negative","expected":null,"passed":true},{"actual":null,"check":"Unicode digit","expected":null,"passed":true},{"actual":["","",""],"check":"empty row","expected":[null,null,null],"passed":false},{"actual":["","cell"],"check":"last slot","expected":[null,"cell"],"passed":false},{"actual":null,"check":"malformed","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"gaps\", \"actual\": [\"cell\", \"\", \"z\", \"\"], \"expected\": [\"cell\", null, \"z\", null], \"passed\": false}, {\"check\": \"equals value\", \"actual\": [\"\", \"a=b\"], \"expected\": [null, \"a=b\"], \"passed\": false}, {\"check\": \"empty value\", \"actual\": [\"\", \"\"], \"expected\": [\"\", null], \"passed\": false}, {\"check\": \"duplicate\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"decreasing\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"out of bounds\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"negative\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"Unicode digit\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty row\", \"actual\": [\"\", \"\", \"\"], \"expected\": [null, null, null], \"passed\": false}, {\"check\": \"last slot\", \"actual\": [\"\", \"cell\"], \"expected\": [null, \"cell\"], \"passed\": false}, {\"check\": \"malformed\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.067,"exit_code":0,"observations":[{"actual":["cell",null,"z",null],"check":"gaps","expected":["cell",null,"z",null],"passed":true},{"actual":[null,"a=b"],"check":"equals value","expected":[null,"a=b"],"passed":true},{"actual":["",null],"check":"empty value","expected":["",null],"passed":true},{"actual":null,"check":"duplicate","expected":null,"passed":true},{"actual":null,"check":"decreasing","expected":null,"passed":true},{"actual":null,"check":"out of bounds","expected":null,"passed":true},{"actual":null,"check":"negative","expected":null,"passed":true},{"actual":null,"check":"Unicode digit","expected":null,"passed":true},{"actual":[null,null,null],"check":"empty row","expected":[null,null,null],"passed":true},{"actual":[null,"cell"],"check":"last slot","expected":[null,"cell"],"passed":true},{"actual":null,"check":"malformed","expected":null,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"gaps\", \"actual\": [\"cell\", null, \"z\", null], \"expected\": [\"cell\", null, \"z\", null], \"passed\": true}, {\"check\": \"equals value\", \"actual\": [null, \"a=b\"], \"expected\": [null, \"a=b\"], \"passed\": true}, {\"check\": \"empty value\", \"actual\": [\"\", null], \"expected\": [\"\", null], \"passed\": true}, {\"check\": \"duplicate\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"decreasing\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"out of bounds\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"negative\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"Unicode digit\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty row\", \"actual\": [null, null, null], \"expected\": [null, null, null], \"passed\": true}, {\"check\": \"last slot\", \"actual\": [null, \"cell\"], \"expected\": [null, \"cell\"], \"passed\": true}, {\"check\": \"malformed\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}