FA-90101 / Bytecode virtual machines / Open access
Upvalues: scope exit leaves its lowest slot on the stack · case 01
Locals declared after a scope ends get shifted slot numbers.
ROOT CAUSE
The stack is truncated one slot above the closing level.
VERIFIED REPAIR
Truncate the stack to exactly level slots.
Unsuccessful approach: Truncating one below the level discards a live enclosing local.
Case contract
A register/stack VM with open and closed upvalues. ["local", v] pushes a slot; ["set", s, v] and ["get", s] access slots; ["closure", id, [slots]] captures slots, reusing the existing open upvalue for a slot so closures share variables; ["uset"/"uget", id, k, (v)] access the k-th upvalue, going to the stack slot while open and to the upvalue's own cell once closed; ["close", level] closes every open upvalue whose slot >= level (copying the slot value) and truncates the stack to level. Accessing a vanished slot appends "dangling-slot" and stops.
Why this case matters
Closure capture and upvalue closing are subtle lifetime transitions in register-based VMs.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(events):
stack = []
open_uv = []
closures = {}
out = []
try:
for ev in events:
op = ev[0]
if op == 'local':
stack.append(ev[1])
elif op == 'set':
stack[ev[1]] = ev[2]
elif op == 'get':
out.append(stack[ev[1]])
elif op == 'closure':
ups = []
for s in ev[2]:
uv = next((u for u in open_uv if u['slot'] == s), None)
if uv is None:
uv = {'slot': s, 'open': True, 'value': None}
open_uv.append(uv)
ups.append(uv)
closures[ev[1]] = ups
elif op == 'uset':
uv = closures[ev[1]][ev[2]]
if uv['open']:
stack[uv['slot']] = ev[3]
else:
uv['value'] = ev[3]
elif op == 'uget':
uv = closures[ev[1]][ev[2]]
out.append(stack[uv['slot']] if uv['open'] else uv['value'])
elif op == 'close':
level = ev[1]
for uv in open_uv:
if uv['slot'] >= level:
uv['value'] = stack[uv['slot']]
uv['open'] = False
open_uv = [u for u in open_uv if u['open']]
del stack[level + 1:]
except IndexError:
out.append('dangling-slot')
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('two closures share one open upvalue',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1]],),
[6, 6]),
('closing a scope keeps closures linked',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[6, 6, 0]),
('regression: new local reusing a closed slot',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[6, 6, 0, 78, 0]),
('open upvalue tracks later stack writes',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 3],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[6, 6, 0, 78, 0, 10, 3, 78]),
('slot reuse after closing everything',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 3],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109]),
('closure over only the outer local',
([['local', 1], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[1, 2]),
('control: plain locals', ([['local', 1], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 1])],
[('two closures share one open upvalue',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1]],),
[7, 7]),
('closing a scope keeps closures linked',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[7, 7, 0]),
('regression: new local reusing a closed slot',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[7, 7, 0, 79, 0]),
('open upvalue tracks later stack writes',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 6],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[7, 7, 0, 79, 0, 20, 6, 79]),
('slot reuse after closing everything',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 6],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[7, 7, 0, 79, 0, 20, 6, 79, 109, 6, 109]),
('closure over only the outer local',
([['local', 2], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[2, 2]),
('control: plain locals', ([['local', 2], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 2])],
[('two closures share one open upvalue',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1]],),
[8, 8]),
('closing a scope keeps closures linked',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[8, 8, 0]),
('regression: new local reusing a closed slot',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[8, 8, 0, 80, 0]),
('open upvalue tracks later stack writes',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 9],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[8, 8, 0, 80, 0, 30, 9, 80]),
('slot reuse after closing everything',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 9],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[8, 8, 0, 80, 0, 30, 9, 80, 109, 9, 109]),
('closure over only the outer local',
([['local', 3], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[3, 2]),
('control: plain locals', ([['local', 3], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 3])],
[('two closures share one open upvalue',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1]],),
[9, 9]),
('closing a scope keeps closures linked',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[9, 9, 0]),
('regression: new local reusing a closed slot',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[9, 9, 0, 81, 0]),
('open upvalue tracks later stack writes',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 12],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[9, 9, 0, 81, 0, 40, 12, 81]),
('slot reuse after closing everything',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 12],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[9, 9, 0, 81, 0, 40, 12, 81, 109, 12, 109]),
('closure over only the outer local',
([['local', 4], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[4, 2]),
('control: plain locals', ([['local', 4], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 4])],
[('two closures share one open upvalue',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1]],),
[10, 10]),
('closing a scope keeps closures linked',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[10, 10, 0]),
('regression: new local reusing a closed slot',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[10, 10, 0, 82, 0]),
('open upvalue tracks later stack writes',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 15],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[10, 10, 0, 82, 0, 50, 15, 82]),
('slot reuse after closing everything',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 15],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[10, 10, 0, 82, 0, 50, 15, 82, 109, 15, 109]),
('closure over only the outer local',
([['local', 5], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[5, 2]),
('control: plain locals', ([['local', 5], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 5])]]
for label, args, expected in cases[N - 1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| two closures share one open upvalue | [6, 6] | [6, 6] | Passed |
| closing a scope keeps closures linked | [6, 6, 0] | [6, 6, 0] | Passed |
| regression: new local reusing a closed slot | [6, 6, 0, 6, 0] | [6, 6, 0, 78, 0] | Failed |
| open upvalue tracks later stack writes | [6, 6, 0, 6, 0, 10, 3, 6] | [6, 6, 0, 78, 0, 10, 3, 78] | Failed |
| slot reuse after closing everything | [6, 6, 0, 6, 0, 10, 3, 6, 3, 3, 3] | [6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109] | Failed |
| closure over only the outer local | [1, 1] | [1, 2] | Failed |
| control: plain locals | [4, 1] | [4, 1] | Passed |
SHA-256 / 3e91da15da7bf4c65fb372703651eb82ea0445dd92fc7becb7c94e3ec724c7df
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(events):
stack = []
open_uv = []
closures = {}
out = []
try:
for ev in events:
op = ev[0]
if op == 'local':
stack.append(ev[1])
elif op == 'set':
stack[ev[1]] = ev[2]
elif op == 'get':
out.append(stack[ev[1]])
elif op == 'closure':
ups = []
for s in ev[2]:
uv = next((u for u in open_uv if u['slot'] == s), None)
if uv is None:
uv = {'slot': s, 'open': True, 'value': None}
open_uv.append(uv)
ups.append(uv)
closures[ev[1]] = ups
elif op == 'uset':
uv = closures[ev[1]][ev[2]]
if uv['open']:
stack[uv['slot']] = ev[3]
else:
uv['value'] = ev[3]
elif op == 'uget':
uv = closures[ev[1]][ev[2]]
out.append(stack[uv['slot']] if uv['open'] else uv['value'])
elif op == 'close':
level = ev[1]
for uv in open_uv:
if uv['slot'] >= level:
uv['value'] = stack[uv['slot']]
uv['open'] = False
open_uv = [u for u in open_uv if u['open']]
del stack[level - 1:]
except IndexError:
out.append('dangling-slot')
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('two closures share one open upvalue',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1]],),
[6, 6]),
('closing a scope keeps closures linked',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[6, 6, 0]),
('regression: new local reusing a closed slot',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[6, 6, 0, 78, 0]),
('open upvalue tracks later stack writes',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 3],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[6, 6, 0, 78, 0, 10, 3, 78]),
('slot reuse after closing everything',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 3],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109]),
('closure over only the outer local',
([['local', 1], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[1, 2]),
('control: plain locals', ([['local', 1], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 1])],
[('two closures share one open upvalue',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1]],),
[7, 7]),
('closing a scope keeps closures linked',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[7, 7, 0]),
('regression: new local reusing a closed slot',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[7, 7, 0, 79, 0]),
('open upvalue tracks later stack writes',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 6],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[7, 7, 0, 79, 0, 20, 6, 79]),
('slot reuse after closing everything',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 6],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[7, 7, 0, 79, 0, 20, 6, 79, 109, 6, 109]),
('closure over only the outer local',
([['local', 2], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[2, 2]),
('control: plain locals', ([['local', 2], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 2])],
[('two closures share one open upvalue',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1]],),
[8, 8]),
('closing a scope keeps closures linked',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[8, 8, 0]),
('regression: new local reusing a closed slot',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[8, 8, 0, 80, 0]),
('open upvalue tracks later stack writes',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 9],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[8, 8, 0, 80, 0, 30, 9, 80]),
('slot reuse after closing everything',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 9],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[8, 8, 0, 80, 0, 30, 9, 80, 109, 9, 109]),
('closure over only the outer local',
([['local', 3], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[3, 2]),
('control: plain locals', ([['local', 3], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 3])],
[('two closures share one open upvalue',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1]],),
[9, 9]),
('closing a scope keeps closures linked',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[9, 9, 0]),
('regression: new local reusing a closed slot',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[9, 9, 0, 81, 0]),
('open upvalue tracks later stack writes',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 12],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[9, 9, 0, 81, 0, 40, 12, 81]),
('slot reuse after closing everything',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 12],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[9, 9, 0, 81, 0, 40, 12, 81, 109, 12, 109]),
('closure over only the outer local',
([['local', 4], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[4, 2]),
('control: plain locals', ([['local', 4], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 4])],
[('two closures share one open upvalue',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1]],),
[10, 10]),
('closing a scope keeps closures linked',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[10, 10, 0]),
('regression: new local reusing a closed slot',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[10, 10, 0, 82, 0]),
('open upvalue tracks later stack writes',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 15],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[10, 10, 0, 82, 0, 50, 15, 82]),
('slot reuse after closing everything',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 15],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[10, 10, 0, 82, 0, 50, 15, 82, 109, 15, 109]),
('closure over only the outer local',
([['local', 5], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[5, 2]),
('control: plain locals', ([['local', 5], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 5])]]
for label, args, expected in cases[N - 1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| two closures share one open upvalue | [6, 6] | [6, 6] | Passed |
| closing a scope keeps closures linked | [6, 6, 0] | [6, 6, 0] | Passed |
| regression: new local reusing a closed slot | [6, 6, 0, 'dangling-slot'] | [6, 6, 0, 78, 0] | Failed |
| open upvalue tracks later stack writes | [6, 6, 0, 'dangling-slot'] | [6, 6, 0, 78, 0, 10, 3, 78] | Failed |
| slot reuse after closing everything | [6, 6, 0, 'dangling-slot'] | [6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109] | Failed |
| closure over only the outer local | [1, 2] | [1, 2] | Passed |
| control: plain locals | [4, 1] | [4, 1] | Passed |
SHA-256 / 9bf6cee2606a492d7d9f76c1dc92e337d21bae8225e14a005220cbc7ab480fe8
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(events):
stack = []
open_uv = []
closures = {}
out = []
try:
for ev in events:
op = ev[0]
if op == 'local':
stack.append(ev[1])
elif op == 'set':
stack[ev[1]] = ev[2]
elif op == 'get':
out.append(stack[ev[1]])
elif op == 'closure':
ups = []
for s in ev[2]:
uv = next((u for u in open_uv if u['slot'] == s), None)
if uv is None:
uv = {'slot': s, 'open': True, 'value': None}
open_uv.append(uv)
ups.append(uv)
closures[ev[1]] = ups
elif op == 'uset':
uv = closures[ev[1]][ev[2]]
if uv['open']:
stack[uv['slot']] = ev[3]
else:
uv['value'] = ev[3]
elif op == 'uget':
uv = closures[ev[1]][ev[2]]
out.append(stack[uv['slot']] if uv['open'] else uv['value'])
elif op == 'close':
level = ev[1]
for uv in open_uv:
if uv['slot'] >= level:
uv['value'] = stack[uv['slot']]
uv['open'] = False
open_uv = [u for u in open_uv if u['open']]
del stack[level:]
except IndexError:
out.append('dangling-slot')
return out
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('two closures share one open upvalue',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1]],),
[6, 6]),
('closing a scope keeps closures linked',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[6, 6, 0]),
('regression: new local reusing a closed slot',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[6, 6, 0, 78, 0]),
('open upvalue tracks later stack writes',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 3],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[6, 6, 0, 78, 0, 10, 3, 78]),
('slot reuse after closing everything',
([['local', 10],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 6],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 78],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 3],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109]),
('closure over only the outer local',
([['local', 1], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[1, 2]),
('control: plain locals', ([['local', 1], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 1])],
[('two closures share one open upvalue',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1]],),
[7, 7]),
('closing a scope keeps closures linked',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[7, 7, 0]),
('regression: new local reusing a closed slot',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[7, 7, 0, 79, 0]),
('open upvalue tracks later stack writes',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 6],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[7, 7, 0, 79, 0, 20, 6, 79]),
('slot reuse after closing everything',
([['local', 20],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 7],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 79],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 6],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[7, 7, 0, 79, 0, 20, 6, 79, 109, 6, 109]),
('closure over only the outer local',
([['local', 2], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[2, 2]),
('control: plain locals', ([['local', 2], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 2])],
[('two closures share one open upvalue',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1]],),
[8, 8]),
('closing a scope keeps closures linked',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[8, 8, 0]),
('regression: new local reusing a closed slot',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[8, 8, 0, 80, 0]),
('open upvalue tracks later stack writes',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 9],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[8, 8, 0, 80, 0, 30, 9, 80]),
('slot reuse after closing everything',
([['local', 30],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 8],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 80],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 9],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[8, 8, 0, 80, 0, 30, 9, 80, 109, 9, 109]),
('closure over only the outer local',
([['local', 3], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[3, 2]),
('control: plain locals', ([['local', 3], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 3])],
[('two closures share one open upvalue',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1]],),
[9, 9]),
('closing a scope keeps closures linked',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[9, 9, 0]),
('regression: new local reusing a closed slot',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[9, 9, 0, 81, 0]),
('open upvalue tracks later stack writes',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 12],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[9, 9, 0, 81, 0, 40, 12, 81]),
('slot reuse after closing everything',
([['local', 40],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 9],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 81],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 12],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[9, 9, 0, 81, 0, 40, 12, 81, 109, 12, 109]),
('closure over only the outer local',
([['local', 4], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[4, 2]),
('control: plain locals', ([['local', 4], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 4])],
[('two closures share one open upvalue',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1]],),
[10, 10]),
('closing a scope keeps closures linked',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1]],),
[10, 10, 0]),
('regression: new local reusing a closed slot',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1]],),
[10, 10, 0, 82, 0]),
('open upvalue tracks later stack writes',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 15],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0]],),
[10, 10, 0, 82, 0, 50, 15, 82]),
('slot reuse after closing everything',
([['local', 50],
['local', 0],
['closure', 'f', [0, 1]],
['closure', 'g', [1]],
['uset', 'f', 1, 10],
['uget', 'g', 0],
['get', 1],
['close', 1],
['uset', 'g', 0, 0],
['uget', 'f', 1],
['local', 82],
['closure', 'h', [1]],
['uget', 'h', 0],
['uget', 'f', 1],
['uget', 'f', 0],
['set', 0, 15],
['uget', 'f', 0],
['close', 0],
['uget', 'h', 0],
['local', 109],
['closure', 'k', [0]],
['uget', 'k', 0],
['uget', 'f', 0],
['get', 0]],),
[10, 10, 0, 82, 0, 50, 15, 82, 109, 15, 109]),
('closure over only the outer local',
([['local', 5], ['closure', 'c', [0]], ['close', 0], ['local', 2], ['uget', 'c', 0], ['get', 0]],),
[5, 2]),
('control: plain locals', ([['local', 5], ['local', 2], ['set', 1, 4], ['get', 1], ['get', 0]],), [4, 5])]]
for label, args, expected in cases[N - 1]:
check(label, solve(*args), expected)
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 |
|---|---|---|---|
| two closures share one open upvalue | [6, 6] | [6, 6] | Passed |
| closing a scope keeps closures linked | [6, 6, 0] | [6, 6, 0] | Passed |
| regression: new local reusing a closed slot | [6, 6, 0, 78, 0] | [6, 6, 0, 78, 0] | Passed |
| open upvalue tracks later stack writes | [6, 6, 0, 78, 0, 10, 3, 78] | [6, 6, 0, 78, 0, 10, 3, 78] | Passed |
| slot reuse after closing everything | [6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109] | [6, 6, 0, 78, 0, 10, 3, 78, 109, 3, 109] | Passed |
| closure over only the outer local | [1, 2] | [1, 2] | Passed |
| control: plain locals | [4, 1] | [4, 1] | Passed |
SHA-256 / b40f53a6d9e9da906a69be80b4a5a5cfe135df9463b5c13c1b0f134eeb6c0f3b
Verification & scope
A deterministic, bounded teaching model of one bytecode virtual machine mechanism with a stipulated instruction encoding; it is not a production VM and claims no conformance to any real specification. 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 2026-09-29T14:51:23.605122+00:00.
Case digest / 66c9de7746ee697ef90ab2d163b4300128524206fcb28ef8954c5e77a5f561dc