{"abstract":"A prefix tokenizer chooses the first rather than longest keyword.","category":"Tokenization","checks":4,"contract":"Return longest prefix among in, int, integer, or None.","contract_signature":"x","evaluation_group":"model-3172e1d9dd6b1754","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-prefix-longest","id":"FA-3876","implementations":{"attempt":{"sha256":"d15622809702d28bf874cbb7826bd5419a68c1f33126657e7e500bb38968f9ac","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 next((p for p in ('int','in','integer') if x.startswith(p)),None)\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('integerx'), 'integer')\ncheck('boundary 2', solve('int32'), 'int')\ncheck('boundary 3', solve('inside'), 'in')\ncheck('boundary 4', solve('else'), 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":"bbf2bf397ec41014d5d808fb7c1593468dbaadf443ac003275aa503527e63b42","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 next((p for p in ('in','int','integer') if x.startswith(p)),None)\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('integerx'), 'integer')\ncheck('boundary 2', solve('int32'), 'int')\ncheck('boundary 3', solve('inside'), 'in')\ncheck('boundary 4', solve('else'), 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-prefix-longest","generated_at":"2026-09-29T14:37:32.189325+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: Return longest prefix among in, int, integer, or None.","sha256":"629faa621541e894afec5061ebf19c4b3677182b38cd3755141afb848bcdba2b","title":"A prefix tokenizer chooses the first rather than longest keyword · 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":50.809,"exit_code":1,"observations":[{"actual":"int","check":"boundary 1","expected":"integer","passed":false},{"actual":"int","check":"boundary 2","expected":"int","passed":true},{"actual":"in","check":"boundary 3","expected":"in","passed":true},{"actual":null,"check":"boundary 4","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"int\", \"expected\": \"integer\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"int\", \"expected\": \"int\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"in\", \"expected\": \"in\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":54.445,"exit_code":1,"observations":[{"actual":"in","check":"boundary 1","expected":"integer","passed":false},{"actual":"in","check":"boundary 2","expected":"int","passed":false},{"actual":"in","check":"boundary 3","expected":"in","passed":true},{"actual":null,"check":"boundary 4","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"in\", \"expected\": \"integer\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"in\", \"expected\": \"int\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"in\", \"expected\": \"in\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": null, \"expected\": null, \"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."}}