{"abstract":"A structured table violates the declared record or column contract.","category":"Delimited text","checks":8,"contract":"Split a simple unquoted comma record and return [value,start,end] for each field, using zero-based Unicode-code-point offsets and exclusive ends. Delimiters are outside field spans; empty fields have equal start/end positions. The input contains no record terminator.","evaluation_group":"s3-delimited-text-field-source-spans","failed_approach":"The alternate implementation still violates the same declared invariant: a field source span starts on its preceding delimiter.","family":"s3-delimited-text-field-source-spans-span-start","id":"FA-48716","implementations":{"attempt":{"sha256":"c6a19efde1c3255c81bc6b25493cebfa072398b59f5bdc55ea76030c33193a6c","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    fields=[]; start=0\n    for position,ch in enumerate(data):\n        if ch==',':\n            fields.append([data[start:position],start,position])\n            start=position+2\n    fields.append([data[start:],start,len(data)])\n    return fields\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('normal', solve(_vary('ab,c')), _vary([['ab', 0, 2], ['c', 3, 4]]))\ncheck('empty edges', solve(_vary(',a,')), _vary([['', 0, 0], ['a', 1, 2], ['', 3, 3]]))\ncheck('empty input', solve(_vary('')), _vary([['', 0, 0]]))\ncheck('unicode', solve(_vary('é,😀')), _vary([['é', 0, 1], ['😀', 2, 3]]))\ncheck('many empties', solve(_vary(',,')), _vary([['', 0, 0], ['', 1, 1], ['', 2, 2]]))\ncheck('one', solve(_vary('abcd')), _vary([['abcd', 0, 4]]))\ncheck('middle empty', solve(_vary('a,,b')), _vary([['a', 0, 1], ['', 2, 2], ['b', 3, 4]]))\ncheck('variant source extent', solve(('x'*N)+',y'), [['x'*N,0,N],['y',N+1,N+2]])\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":"813b50ab01582da8c8eb9ecd4f9816d52ea653af05c44044d2dcb8dc1ce020fd","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    fields=[]; start=0\n    for position,ch in enumerate(data):\n        if ch==',':\n            fields.append([data[start:position],start,position])\n            start=position\n    fields.append([data[start:],start,len(data)])\n    return fields\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('normal', solve(_vary('ab,c')), _vary([['ab', 0, 2], ['c', 3, 4]]))\ncheck('empty edges', solve(_vary(',a,')), _vary([['', 0, 0], ['a', 1, 2], ['', 3, 3]]))\ncheck('empty input', solve(_vary('')), _vary([['', 0, 0]]))\ncheck('unicode', solve(_vary('é,😀')), _vary([['é', 0, 1], ['😀', 2, 3]]))\ncheck('many empties', solve(_vary(',,')), _vary([['', 0, 0], ['', 1, 1], ['', 2, 2]]))\ncheck('one', solve(_vary('abcd')), _vary([['abcd', 0, 4]]))\ncheck('middle empty', solve(_vary('a,,b')), _vary([['a', 0, 1], ['', 2, 2], ['b', 3, 4]]))\ncheck('variant source extent', solve(('x'*N)+',y'), [['x'*N,0,N],['y',N+1,N+2]])\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":"36d88f5387bcb781d1af648c07014ef487be5bdb8e70990a67002beb75f82ffa","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    fields=[]; start=0\n    for position,ch in enumerate(data):\n        if ch==',':\n            fields.append([data[start:position],start,position])\n            start=position+1\n    fields.append([data[start:],start,len(data)])\n    return fields\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('normal', solve(_vary('ab,c')), _vary([['ab', 0, 2], ['c', 3, 4]]))\ncheck('empty edges', solve(_vary(',a,')), _vary([['', 0, 0], ['a', 1, 2], ['', 3, 3]]))\ncheck('empty input', solve(_vary('')), _vary([['', 0, 0]]))\ncheck('unicode', solve(_vary('é,😀')), _vary([['é', 0, 1], ['😀', 2, 3]]))\ncheck('many empties', solve(_vary(',,')), _vary([['', 0, 0], ['', 1, 1], ['', 2, 2]]))\ncheck('one', solve(_vary('abcd')), _vary([['abcd', 0, 4]]))\ncheck('middle empty', solve(_vary('a,,b')), _vary([['a', 0, 1], ['', 2, 2], ['b', 3, 4]]))\ncheck('variant source extent', solve(('x'*N)+',y'), [['x'*N,0,N],['y',N+1,N+2]])\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-field-source-spans-span-start","generated_at":"2026-09-29T14:44:53.272140+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: start=position+1","root_cause":"A field source span starts on its preceding delimiter.","sha256":"278fffc1fc8d00f19cad5246284a7435a974ccd57b1a2b56f26582785962aeaf","title":"A field source span starts on its preceding delimiter · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.568,"exit_code":1,"observations":[{"actual":[["ab",0,2],["",4,4]],"check":"normal","expected":[["ab",0,2],["c",3,4]],"passed":false},{"actual":[["",0,0],["",2,2],["",4,3]],"check":"empty edges","expected":[["",0,0],["a",1,2],["",3,3]],"passed":false},{"actual":[["",0,0]],"check":"empty input","expected":[["",0,0]],"passed":true},{"actual":[["é",0,1],["",3,3]],"check":"unicode","expected":[["é",0,1],["😀",2,3]],"passed":false},{"actual":[["",0,0],["",2,1],["",3,2]],"check":"many empties","expected":[["",0,0],["",1,1],["",2,2]],"passed":false},{"actual":[["abcd",0,4]],"check":"one","expected":[["abcd",0,4]],"passed":true},{"actual":[["a",0,1],["",3,2],["",4,4]],"check":"middle empty","expected":[["a",0,1],["",2,2],["b",3,4]],"passed":false},{"actual":[["x",0,1],["",3,3]],"check":"variant source extent","expected":[["x",0,1],["y",2,3]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal\", \"actual\": [[\"ab\", 0, 2], [\"\", 4, 4]], \"expected\": [[\"ab\", 0, 2], [\"c\", 3, 4]], \"passed\": false}, {\"check\": \"empty edges\", \"actual\": [[\"\", 0, 0], [\"\", 2, 2], [\"\", 4, 3]], \"expected\": [[\"\", 0, 0], [\"a\", 1, 2], [\"\", 3, 3]], \"passed\": false}, {\"check\": \"empty input\", \"actual\": [[\"\", 0, 0]], \"expected\": [[\"\", 0, 0]], \"passed\": true}, {\"check\": \"unicode\", \"actual\": [[\"é\", 0, 1], [\"\", 3, 3]], \"expected\": [[\"é\", 0, 1], [\"😀\", 2, 3]], \"passed\": false}, {\"check\": \"many empties\", \"actual\": [[\"\", 0, 0], [\"\", 2, 1], [\"\", 3, 2]], \"expected\": [[\"\", 0, 0], [\"\", 1, 1], [\"\", 2, 2]], \"passed\": false}, {\"check\": \"one\", \"actual\": [[\"abcd\", 0, 4]], \"expected\": [[\"abcd\", 0, 4]], \"passed\": true}, {\"check\": \"middle empty\", \"actual\": [[\"a\", 0, 1], [\"\", 3, 2], [\"\", 4, 4]], \"expected\": [[\"a\", 0, 1], [\"\", 2, 2], [\"b\", 3, 4]], \"passed\": false}, {\"check\": \"variant source extent\", \"actual\": [[\"x\", 0, 1], [\"\", 3, 3]], \"expected\": [[\"x\", 0, 1], [\"y\", 2, 3]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.386,"exit_code":1,"observations":[{"actual":[["ab",0,2],[",c",2,4]],"check":"normal","expected":[["ab",0,2],["c",3,4]],"passed":false},{"actual":[["",0,0],[",a",0,2],[",",2,3]],"check":"empty edges","expected":[["",0,0],["a",1,2],["",3,3]],"passed":false},{"actual":[["",0,0]],"check":"empty input","expected":[["",0,0]],"passed":true},{"actual":[["é",0,1],[",😀",1,3]],"check":"unicode","expected":[["é",0,1],["😀",2,3]],"passed":false},{"actual":[["",0,0],[",",0,1],[",",1,2]],"check":"many empties","expected":[["",0,0],["",1,1],["",2,2]],"passed":false},{"actual":[["abcd",0,4]],"check":"one","expected":[["abcd",0,4]],"passed":true},{"actual":[["a",0,1],[",",1,2],[",b",2,4]],"check":"middle empty","expected":[["a",0,1],["",2,2],["b",3,4]],"passed":false},{"actual":[["x",0,1],[",y",1,3]],"check":"variant source extent","expected":[["x",0,1],["y",2,3]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal\", \"actual\": [[\"ab\", 0, 2], [\",c\", 2, 4]], \"expected\": [[\"ab\", 0, 2], [\"c\", 3, 4]], \"passed\": false}, {\"check\": \"empty edges\", \"actual\": [[\"\", 0, 0], [\",a\", 0, 2], [\",\", 2, 3]], \"expected\": [[\"\", 0, 0], [\"a\", 1, 2], [\"\", 3, 3]], \"passed\": false}, {\"check\": \"empty input\", \"actual\": [[\"\", 0, 0]], \"expected\": [[\"\", 0, 0]], \"passed\": true}, {\"check\": \"unicode\", \"actual\": [[\"é\", 0, 1], [\",😀\", 1, 3]], \"expected\": [[\"é\", 0, 1], [\"😀\", 2, 3]], \"passed\": false}, {\"check\": \"many empties\", \"actual\": [[\"\", 0, 0], [\",\", 0, 1], [\",\", 1, 2]], \"expected\": [[\"\", 0, 0], [\"\", 1, 1], [\"\", 2, 2]], \"passed\": false}, {\"check\": \"one\", \"actual\": [[\"abcd\", 0, 4]], \"expected\": [[\"abcd\", 0, 4]], \"passed\": true}, {\"check\": \"middle empty\", \"actual\": [[\"a\", 0, 1], [\",\", 1, 2], [\",b\", 2, 4]], \"expected\": [[\"a\", 0, 1], [\"\", 2, 2], [\"b\", 3, 4]], \"passed\": false}, {\"check\": \"variant source extent\", \"actual\": [[\"x\", 0, 1], [\",y\", 1, 3]], \"expected\": [[\"x\", 0, 1], [\"y\", 2, 3]], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.494,"exit_code":0,"observations":[{"actual":[["ab",0,2],["c",3,4]],"check":"normal","expected":[["ab",0,2],["c",3,4]],"passed":true},{"actual":[["",0,0],["a",1,2],["",3,3]],"check":"empty edges","expected":[["",0,0],["a",1,2],["",3,3]],"passed":true},{"actual":[["",0,0]],"check":"empty input","expected":[["",0,0]],"passed":true},{"actual":[["é",0,1],["😀",2,3]],"check":"unicode","expected":[["é",0,1],["😀",2,3]],"passed":true},{"actual":[["",0,0],["",1,1],["",2,2]],"check":"many empties","expected":[["",0,0],["",1,1],["",2,2]],"passed":true},{"actual":[["abcd",0,4]],"check":"one","expected":[["abcd",0,4]],"passed":true},{"actual":[["a",0,1],["",2,2],["b",3,4]],"check":"middle empty","expected":[["a",0,1],["",2,2],["b",3,4]],"passed":true},{"actual":[["x",0,1],["y",2,3]],"check":"variant source extent","expected":[["x",0,1],["y",2,3]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal\", \"actual\": [[\"ab\", 0, 2], [\"c\", 3, 4]], \"expected\": [[\"ab\", 0, 2], [\"c\", 3, 4]], \"passed\": true}, {\"check\": \"empty edges\", \"actual\": [[\"\", 0, 0], [\"a\", 1, 2], [\"\", 3, 3]], \"expected\": [[\"\", 0, 0], [\"a\", 1, 2], [\"\", 3, 3]], \"passed\": true}, {\"check\": \"empty input\", \"actual\": [[\"\", 0, 0]], \"expected\": [[\"\", 0, 0]], \"passed\": true}, {\"check\": \"unicode\", \"actual\": [[\"é\", 0, 1], [\"😀\", 2, 3]], \"expected\": [[\"é\", 0, 1], [\"😀\", 2, 3]], \"passed\": true}, {\"check\": \"many empties\", \"actual\": [[\"\", 0, 0], [\"\", 1, 1], [\"\", 2, 2]], \"expected\": [[\"\", 0, 0], [\"\", 1, 1], [\"\", 2, 2]], \"passed\": true}, {\"check\": \"one\", \"actual\": [[\"abcd\", 0, 4]], \"expected\": [[\"abcd\", 0, 4]], \"passed\": true}, {\"check\": \"middle empty\", \"actual\": [[\"a\", 0, 1], [\"\", 2, 2], [\"b\", 3, 4]], \"expected\": [[\"a\", 0, 1], [\"\", 2, 2], [\"b\", 3, 4]], \"passed\": true}, {\"check\": \"variant source extent\", \"actual\": [[\"x\", 0, 1], [\"y\", 2, 3]], \"expected\": [[\"x\", 0, 1], [\"y\", 2, 3]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}