FA-3586 / Lexical grammars / Open access

A prerelease identifier is empty after a separator · case 01

A prerelease identifier is empty after a separator.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The recognizer uses '[0-9]+\\.[0-9]+\\.[0-9]+(?:-[A-Za-z0-9.-]*)?', which admits or omits a token shape forbidden by the stated grammar.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Accept three decimal components and optional hyphen-prefixed dot-separated nonempty alphanumeric/hyphen identifiers.

Unsuccessful approach: The candidate grammar '[0-9]+\\.[0-9]+\\.[0-9]+(?:-[A-Za-z0-9.-]+)?' still disagrees with the explicit boundary fixtures.

Case contract

Accept three decimal components and optional hyphen-prefixed dot-separated nonempty alphanumeric/hyphen identifiers.

Why this case matters

A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return bool(re.fullmatch('[0-9]+\\.[0-9]+\\.[0-9]+(?:-[A-Za-z0-9.-]*)?',x))
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('1.2.3-'), False)
check('boundary 2', solve('1.2.3-a..b'), False)
check('boundary 3', solve('1.2.3-alpha.1'), True)
check('boundary 4', solve('1.2.3'), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
boundary 1	`True`	`False`	Failed
boundary 2	`True`	`False`	Failed
boundary 3	`True`	`True`	Passed
boundary 4	`True`	`True`	Passed

SHA-256 / 2c6d7302abd8304295e61ecdd88f3e0f589e41ad1d7f2eda97c039733fe0657e

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return bool(re.fullmatch('[0-9]+\\.[0-9]+\\.[0-9]+(?:-[A-Za-z0-9.-]+)?',x))
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('1.2.3-'), False)
check('boundary 2', solve('1.2.3-a..b'), False)
check('boundary 3', solve('1.2.3-alpha.1'), True)
check('boundary 4', solve('1.2.3'), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
boundary 1	`False`	`False`	Passed
boundary 2	`True`	`False`	Failed
boundary 3	`True`	`True`	Passed
boundary 4	`True`	`True`	Passed

SHA-256 / ee3188127378446da3ad859345511502243a88481c945ed47fefcdce9ca8c34d

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return bool(re.fullmatch('[0-9]+\\.[0-9]+\\.[0-9]+(?:-[A-Za-z0-9-]+(?:\\.[A-Za-z0-9-]+)*)?',x))
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('1.2.3-'), False)
check('boundary 2', solve('1.2.3-a..b'), False)
check('boundary 3', solve('1.2.3-alpha.1'), True)
check('boundary 4', solve('1.2.3'), True)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
boundary 1	`False`	`False`	Passed
boundary 2	`False`	`False`	Passed
boundary 3	`True`	`True`	Passed
boundary 4	`True`	`True`	Passed

SHA-256 / 260b2327603b885600daba0e897e0193007756f753a701addbfbc9aefb2cc4e4

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:37:28.024657+00:00.

Case digest / 947f89d20b1f7f919d0f0d702d28aa0969fa49cf9b80b882f78b63d96dadbdc2