FAILURE MAP
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Hangul syllables bypass canonical decomposition · case 01

Hangul syllables bypass canonical decomposition.

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

ROOT CAUSE

The implementation applies an operation whose text or grammar semantics violate this contract: Produce canonical NFD decomposition; retain compatibility glyphs.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Produce canonical NFD decomposition; retain compatibility glyphs.

Unsuccessful approach: The attempted repair handles the primary example but still violates a separate boundary of the same contract.

Case contract

Produce canonical NFD decomposition; retain compatibility glyphs.

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 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('가'), '가')
check('boundary 2', solve('é'), 'é')
check('boundary 3', solve('①'), '①')
check('boundary 4', solve('A'), 'A')
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 fixtureActualExpectedOutcome
boundary 1가가Failed
boundary 2ééFailed
boundary 3①①Passed
boundary 4AAPassed

SHA-256 / 8bdd8a946367f738c2c47eda3a16508cee3737eb4493eb37531398724e15ea2c

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 ''.join(c for c in unicodedata.normalize('NFKD', 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('가'), '가')
check('boundary 2', solve('é'), 'é')
check('boundary 3', solve('①'), '①')
check('boundary 4', solve('A'), 'A')
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 fixtureActualExpectedOutcome
boundary 1가가Passed
boundary 2ééPassed
boundary 31①Failed
boundary 4AAPassed

SHA-256 / 0fd07f0ae3e558a77b28044bf77ac32da3f3c1318ec56030629127035c6884ea

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 unicodedata.normalize('NFD', 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('가'), '가')
check('boundary 2', solve('é'), 'é')
check('boundary 3', solve('①'), '①')
check('boundary 4', solve('A'), 'A')
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 fixtureActualExpectedOutcome
boundary 1가가Passed
boundary 2ééPassed
boundary 3①①Passed
boundary 4AAPassed

SHA-256 / bdf0aa588bc798567c4513dd79d16cc4bfbb9fc142a89060091a5097d12f3ab5

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 2026-09-29T14:37:18.014840+00:00.

Case digest / 720dd90d417b264a4ef481d35f8c5fee0b7d71656fdd934ff7c1388dd1806af2