fix(python): slice must not treat a boolean as a number - #85
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Python's bool is a subclass of int, so `isinstance(val, (int, float))`
sent booleans down slice's numeric clamp path:
slice(True, 1) -> 1 (canonical: True)
slice(True, 0, 1) -> 0 (canonical: True)
slice(False, 1) -> 1 (canonical: False)
Canonical StructUtility.ts guards with `S_number === typeof val`, and
`typeof true` is "boolean", so a boolean falls through to the container
path and is returned unchanged. Excluding bool restores that.
The corpus cannot catch this, in this port or any other: the in-situ
runner compares results with plain `==`, under which `1 == True`, so the
wrong value passes. It surfaced while running the suite under voxgig/omni,
whose deepequal refuses to conflate booleans with numbers. Worth pinning
with a corpus entry once enough ports run under a strict comparison to
make the entry mean something; recorded in omni's handover note.
The other dynamic ports were checked and already guard: Ruby excludes
TrueClass/FalseClass explicitly, Perl requires !ref (JSON booleans are
blessed refs), PHP's is_numeric(true) is false, and Lua's type(true) is
"boolean".
python: 100 tests, 3 skipped, OK - unchanged from before the fix, as
expected given the `==` comparison.
Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EHLH9d5Jaiy6QbMKja22nt
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Python's
boolis a subclass ofint, soisinstance(val, (int, float))sent booleans downslice's numeric clamp path:slice(True, 1)True1Trueslice(True, 0, 1)True0Trueslice(False, 1)False1FalseCanonical
StructUtility.tsguards withS_number === typeof val, andtypeof trueis"boolean", so a boolean falls through to the container path and is returned unchanged. Excludingboolrestores that.Why the corpus did not catch it
It cannot — not in this port or any other. The in-situ runner compares results with plain
==, under which1 == True, so the wrong value passes. It surfaced while running the python suite undervoxgig/omni, whosedeepequalrefuses to conflate booleans with numbers.Worth pinning with a corpus entry once enough ports run under a strict comparison for the entry to mean something; that is recorded in omni's handover note rather than added here, where it would be toothless.
Other ports
Checked, and all four already guard: Ruby excludes
TrueClass/FalseClassexplicitly, Perl requires!ref(JSON booleans are blessed refs), PHP'sis_numeric(true)isfalse, and Lua'stype(true)is"boolean".Verification
cd python && python3 -m unittest discover -s tests— 100 tests, 3 skipped, OK. Unchanged from before the fix, as expected given the==comparison; the fix is verified directly against canonicalsliceoutput for the cases in the table.Generated by Claude Code