FA-48391 / Delimited text / Open access

Incoming column indexes are used in the inverse direction · case 01

A structured table violates the declared record or column contract.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Incoming column indexes are used in the inverse direction.

THE FAILURE

Incoming column indexes are used in the inverse direction.

Unsuccessful approach: The alternate implementation still violates the same declared invariant: incoming column indexes are used in the inverse direction.

Case contract

Process an initial comma header plus ORDER|comma-indexes and DATA|comma-values records. ORDER is a zero-based permutation describing each incoming position original column index. Each new order replaces the previous order. DATA is rearranged into original header order. Reject invalid permutations and row widths.

Why this case matters

Delimited interchange needs explicit framing, schema and field semantics at ingestion and emission boundaries.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
def _vary(value):
    if value == '@END': return 3 + 4*N
    if isinstance(value, str): return value.replace('@', 'cell' * N)
    if isinstance(value, list): return [_vary(x) for x in value]
    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}
    return value
N = 1
observations = []
def solve(data):
    width=len(data[0].split(',')); order=list(range(width)); rows=[]
    for line in data[1:]:
        tag,payload=(line.split('|',1)+[''])[:2]
        fields=payload.split(',')
        if tag=='ORDER':
            if any(not x.isascii() or not x.isdecimal() for x in fields): return None
            proposal=[int(x) for x in fields]
            if sorted(proposal)!=list(range(width)): return None
            order=proposal
        elif tag=='DATA':
            if len(fields)!=width: return None
            row=[None]*width
            for position,original in enumerate(order): row[position]=fields[original]
            rows.append(row)
        else: return None
    return rows
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('cyclic', solve(_vary(['a,b,c', 'ORDER|2,0,1', 'DATA|z,@,y'])), _vary([['@', 'y', 'z']]))
check('replace', solve(_vary(['a,b,c', 'ORDER|2,0,1', 'ORDER|1,2,0', 'DATA|y,z,@'])), _vary([['@', 'y', 'z']]))
check('duplicate order', solve(_vary(['a,b', 'ORDER|0,0'])), _vary(None))
check('out of range', solve(_vary(['a,b', 'ORDER|0,2'])), _vary(None))
check('wrong width', solve(_vary(['a,b', 'DATA|@'])), _vary(None))
check('identity', solve(_vary(['a,b', 'DATA|@,z'])), _vary([['@', 'z']]))
check('reset', solve(_vary(['a,b', 'ORDER|1,0', 'DATA|x,@', 'ORDER|0,1', 'DATA|@,y'])), _vary([['@', 'x'], ['@', 'y']]))
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
cyclic	`[['y', 'z', 'cell']]`	`[['cell', 'y', 'z']]`	Failed
replace	`[['z', 'cell', 'y']]`	`[['cell', 'y', 'z']]`	Failed
duplicate order	`None`	`None`	Passed
out of range	`None`	`None`	Passed
wrong width	`None`	`None`	Passed
identity	`[['cell', 'z']]`	`[['cell', 'z']]`	Passed
reset	`[['cell', 'x'], ['cell', 'y']]`	`[['cell', 'x'], ['cell', 'y']]`	Passed

SHA-256 / e126168aff5f7abccd6eaa2ca430b9071d9cb3722a0a5c2361d215f141ad674e

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
def _vary(value):
    if value == '@END': return 3 + 4*N
    if isinstance(value, str): return value.replace('@', 'cell' * N)
    if isinstance(value, list): return [_vary(x) for x in value]
    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}
    return value
N = 1
observations = []
def solve(data):
    width=len(data[0].split(',')); order=list(range(width)); rows=[]
    for line in data[1:]:
        tag,payload=(line.split('|',1)+[''])[:2]
        fields=payload.split(',')
        if tag=='ORDER':
            if any(not x.isascii() or not x.isdecimal() for x in fields): return None
            proposal=[int(x) for x in fields]
            if sorted(proposal)!=list(range(width)): return None
            order=proposal
        elif tag=='DATA':
            if len(fields)!=width: return None
            row=[None]*width
            for position,original in enumerate(order): row[position]=fields[position]
            rows.append(row)
        else: return None
    return rows
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('cyclic', solve(_vary(['a,b,c', 'ORDER|2,0,1', 'DATA|z,@,y'])), _vary([['@', 'y', 'z']]))
check('replace', solve(_vary(['a,b,c', 'ORDER|2,0,1', 'ORDER|1,2,0', 'DATA|y,z,@'])), _vary([['@', 'y', 'z']]))
check('duplicate order', solve(_vary(['a,b', 'ORDER|0,0'])), _vary(None))
check('out of range', solve(_vary(['a,b', 'ORDER|0,2'])), _vary(None))
check('wrong width', solve(_vary(['a,b', 'DATA|@'])), _vary(None))
check('identity', solve(_vary(['a,b', 'DATA|@,z'])), _vary([['@', 'z']]))
check('reset', solve(_vary(['a,b', 'ORDER|1,0', 'DATA|x,@', 'ORDER|0,1', 'DATA|@,y'])), _vary([['@', 'x'], ['@', 'y']]))
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
cyclic	`[['z', 'cell', 'y']]`	`[['cell', 'y', 'z']]`	Failed
replace	`[['y', 'z', 'cell']]`	`[['cell', 'y', 'z']]`	Failed
duplicate order	`None`	`None`	Passed
out of range	`None`	`None`	Passed
wrong width	`None`	`None`	Passed
identity	`[['cell', 'z']]`	`[['cell', 'z']]`	Passed
reset	`[['x', 'cell'], ['cell', 'y']]`	`[['cell', 'x'], ['cell', 'y']]`	Failed

SHA-256 / ef16b198ee4329f4ff1ec5b8cb18038b33c2882431282efe8b5336dd9aa7422b

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 7 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Deterministic bounded in-memory model. No claim of complete CSV or external format conformance. 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 2026-09-29T14:44:50.539296+00:00.

Case digest / c82ac89f81eca3a92b78f94d3b59fe190c5080b66d975956fa6a9720fa42e06d