Shape Number/%TypedArray% constructors and %TypedArray%.prototype; add [JsInstanceSlot]#2581
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- NumberConstructor: Number.parseInt / parseFloat are the same functions as the global parseInt / parseFloat (Jint's ClrFunction equality compares the underlying delegate). They wrap static delegates with no realm dependency, so — like RegExp exec — they become per-realm [JsProperty] ClrFunction instance slots created in the constructor. The hand-written SetProperty tail + ExtraCapacity are gone. - IntrinsicTypedArrayConstructor (%TypedArray%): clean (from/of + @@species symbol accessor); opts in directly. Benchmarks (BuiltinShapeBenchmark, default job, vs prior commit; EngineOnly control byte- identical at 13.70 KB): EngineInitConstructors (extended to touch Number/%TypedArray%) 50.51 -> 49.58 KB (-0.93 KB). Conformance: full Test262 0 new failures (only the pre-existing annexB RegExp-*-escape-BMP concurrent-load flakes). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018Fq5mF1QEwh2qDMD8vVwt3
…totype
Add a [JsInstanceSlot("name")] class-level attribute that reserves a per-realm own-property
slot (appended after all other own properties, matching a hand-written SetProperty tail) which
the host fills in Initialize via SetBuiltinSlotByName(name, descriptor). This expresses a
computed/lazy value the generator can't — specifically a cross-object alias.
Use it for %TypedArray%.prototype.toString, which per spec is the SAME function object as
%Array.prototype.toString% (a different-host alias resolved lazily per realm). This unblocks the
37-member IntrinsicTypedArrayPrototype (10 accessors, ~20 methods, @@iterator === values); its
ExtraCapacity + the raw _properties.AddDangerous("toString", ...) tail are gone. Resolution stays
lazy, so touching %TypedArray%.prototype does not force Array init.
Benchmarks (BuiltinShapeBenchmark, default job, vs prior commit; EngineOnly control byte-
identical at 13.70 KB): EngineInitPrototypes (extended to touch %TypedArray%.prototype)
84.83 -> 81.14 KB (-3.69 KB).
Conformance: full Test262 0 new failures (only the pre-existing annexB RegExp-*-escape-BMP
concurrent-load flakes); Jint.Tests.SourceGenerators 30/30 (snapshot updated for the attribute).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018Fq5mF1QEwh2qDMD8vVwt3
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Summary
Follow-up to #2580 — shapes three more built-in hosts, including the last big one, and adds a small reusable generator mechanism for host-computed properties.
Number.parseInt/parseFloatare the same functions as globalparseInt/parseFloat(Jint'sClrFunctionequality compares the underlying delegate). They wrap static delegates with no realm dependency, so — likeRegExp.prototype.execin Built-in shapes for prototypes and constructors: composable storage, accessors, aliases #2580 — they become per-realm[JsProperty]ClrFunctioninstance slots created in the constructor. Hand-writtenSetPropertytail +ExtraCapacitygone.%TypedArray%) — clean (from/of+@@species); opts in directly.[JsInstanceSlot("name")]— reserves a per-realm own-property slot (appended after all other own properties) that the host fills inInitializeviaSetBuiltinSlotByName(name, descriptor), for a computed/lazy value the generator can't express (specifically a cross-object alias).%TypedArray%.prototype, 37 members: 10 accessors, ~20 methods,@@iterator === values) — itstoStringis the same function object as%Array.prototype.toString%, a lazy cross-object alias, now expressed via[JsInstanceSlot]. Resolution stays lazy, so touching%TypedArray%.prototypedoesn't forceArrayinit.Benchmarks
Jint.Benchmark/BuiltinShapeBenchmark.cs, default job. Each commit A/B'd against a byte-identicalEngineOnlycontrol (13.70 KB); per-realmInitializeallocation removed:%TypedArray%constructorEngineInitConstructors50.51 → 49.58 KB (−0.93 KB)[JsInstanceSlot]+%TypedArray%.prototypeEngineInitPrototypes84.83 → 81.14 KB (−3.69 KB)Conformance
annexB RegExp-*-escape-BMPconcurrent-load timeout flakes).Remaining (deliberately on the dictionary path)
The TypedArray constructor hierarchy (
Uint8ArrayConstructorwould re-implementIBuiltinShapedwith only its own members, dropping the inheritedBYTES_PER_ELEMENTfrom the abstract base's shape — needs generator support for inherited[JsObject]members),RegExpConstructorlegacy statics, and the intrinsic-reference / thrower hosts (GlobalObject, Intl/Temporal instances,FunctionPrototype).🤖 Generated with Claude Code
https://claude.ai/code/session_018Fq5mF1QEwh2qDMD8vVwt3