{"abstract":"Split delimiters unexpectedly enter the result.","category":"Regular expressions","checks":4,"contract":"Split on one or more comma/semicolon delimiters while preserving terminal empty fields.","evaluation_group":"model-4e641c6889604b8f","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-regex-capture-split","id":"FA-3096","implementations":{"attempt":{"sha256":"41b8360e39d4e91bda73eb7f7dac645345be5c8bb51cac432c295697367a03a6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return [v for v in re.split(r'[,;]+',x) if v]\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve('a,b;c'), ['a', 'b', 'c'])\ncheck('boundary 2', solve(',a,'), ['', 'a', ''])\ncheck('boundary 3', solve('a,,b'), ['a', 'b'])\ncheck('boundary 4', solve(''), [''])\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":"5724ace7773d44b064217b56e9d7a9a7d23f2d4441ecfbcaf5c40960a5d80d33","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return re.split(r'([,;]+)',x)\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve('a,b;c'), ['a', 'b', 'c'])\ncheck('boundary 2', solve(',a,'), ['', 'a', ''])\ncheck('boundary 3', solve('a,,b'), ['a', 'b'])\ncheck('boundary 4', solve(''), [''])\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":"00bfb53f4185964d5be2c6eb4380cd524a886fcc8ae3f4a200f616e5a4d029e4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        return re.split(r'[,;]+',x)\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve('a,b;c'), ['a', 'b', 'c'])\ncheck('boundary 2', solve(',a,'), ['', 'a', ''])\ncheck('boundary 3', solve('a,,b'), ['a', 'b'])\ncheck('boundary 4', solve(''), [''])\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":"xp-regex-capture-split","generated_at":"2026-09-29T14:37:21.353061+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.","repair":"Implement the complete stated contract, including the boundary fixtures: Split on one or more comma/semicolon delimiters while preserving terminal empty fields.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Split on one or more comma/semicolon delimiters while preserving terminal empty fields.","sha256":"f5a0aeb662846fc7ebd860f8c764b7681270b765a3971b79f469c53304165665","title":"Split delimiters unexpectedly enter the result · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":58.942,"exit_code":1,"observations":[{"actual":["a","b","c"],"check":"boundary 1","expected":["a","b","c"],"passed":true},{"actual":["a"],"check":"boundary 2","expected":["","a",""],"passed":false},{"actual":["a","b"],"check":"boundary 3","expected":["a","b"],"passed":true},{"actual":[],"check":"boundary 4","expected":[""],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"a\", \"b\", \"c\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [\"a\"], \"expected\": [\"\", \"a\", \"\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\"], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [], \"expected\": [\"\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":54.468,"exit_code":1,"observations":[{"actual":["a",",","b",";","c"],"check":"boundary 1","expected":["a","b","c"],"passed":false},{"actual":["",",","a",",",""],"check":"boundary 2","expected":["","a",""],"passed":false},{"actual":["a",",,","b"],"check":"boundary 3","expected":["a","b"],"passed":false},{"actual":[""],"check":"boundary 4","expected":[""],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"a\", \",\", \"b\", \";\", \"c\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [\"\", \",\", \"a\", \",\", \"\"], \"expected\": [\"\", \"a\", \"\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [\"a\", \",,\", \"b\"], \"expected\": [\"a\", \"b\"], \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":54.57,"exit_code":0,"observations":[{"actual":["a","b","c"],"check":"boundary 1","expected":["a","b","c"],"passed":true},{"actual":["","a",""],"check":"boundary 2","expected":["","a",""],"passed":true},{"actual":["a","b"],"check":"boundary 3","expected":["a","b"],"passed":true},{"actual":[""],"check":"boundary 4","expected":[""],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"a\", \"b\", \"c\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [\"\", \"a\", \"\"], \"expected\": [\"\", \"a\", \"\"], \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": [\"a\", \"b\"], \"expected\": [\"a\", \"b\"], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}