{"abstract":"A minimal token matcher yields empty tokens between characters.","category":"Regular expressions","checks":4,"contract":"Extract nonempty quoted bodies, allowing backslash-escaped characters.","contract_signature":"x","evaluation_group":"model-4efed64c238c32b4","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-regex-lazy-empty","id":"FA-3916","implementations":{"attempt":{"sha256":"f63bd2de7b2b0dcf318a07660d5cf05ea2f833761fc58137cac4c63edb713855","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.findall(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('\"\"'), [])\ncheck('boundary 2', solve('\"a\\\\\"b\"'), ['a\\\\\"b'])\ncheck('boundary 3', solve('\"abc\"'), ['abc'])\ncheck('boundary 4', solve('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":"58204faece05da6fea2b1bb246b56086029603f3fea6cd40f4d4e1130bce7b63","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.findall(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('\"\"'), [])\ncheck('boundary 2', solve('\"a\\\\\"b\"'), ['a\\\\\"b'])\ncheck('boundary 3', solve('\"abc\"'), ['abc'])\ncheck('boundary 4', solve('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":" 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-lazy-empty","generated_at":"2026-09-29T14:37:32.784531+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.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Extract nonempty quoted bodies, allowing backslash-escaped characters.","sha256":"d07d01db945b2a8506a1b433d1d211f3bf7880b9e1e27390749724e898155dbf","title":"A minimal token matcher yields empty tokens between characters · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":57.345,"exit_code":1,"observations":[{"actual":[],"check":"boundary 1","expected":[],"passed":true},{"actual":["a\\"],"check":"boundary 2","expected":["a\\\"b"],"passed":false},{"actual":["abc"],"check":"boundary 3","expected":["abc"],"passed":true},{"actual":[],"check":"boundary 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [\"a\\\\\"], \"expected\": [\"a\\\\\\\"b\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [\"abc\"], \"expected\": [\"abc\"], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":54.937,"exit_code":1,"observations":[{"actual":[""],"check":"boundary 1","expected":[],"passed":false},{"actual":["a\\"],"check":"boundary 2","expected":["a\\\"b"],"passed":false},{"actual":["abc"],"check":"boundary 3","expected":["abc"],"passed":true},{"actual":[],"check":"boundary 4","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"\"], \"expected\": [], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [\"a\\\\\"], \"expected\": [\"a\\\\\\\"b\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [\"abc\"], \"expected\": [\"abc\"], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": [], \"expected\": [], \"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."}}