mirror of
https://github.com/vercel-labs/scriptc.git
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Chris Tate
6b6445ab90
- The ratified rename rider (world-unification §7 lane 5): "DOM" collided with the browser DOM and, post-lane-1, the structure is no longer a document tree. Comments and doc prose now say "the checked-dynamic tree" for the noun and "dyn" adjectivally; runtime symbol names (scr_dyn_*), the error.domClone libCall, and the real web DOMException family are unchanged. - The few user-facing strings carrying the nickname move with it (the structuredClone cyclic message, the dc subscriber/publish fences, two emitter ICE texts); diagnostics snapshots regenerated (96 pass). One private compiler constant (DOM_PROTO_METHOD_NAMES -> DYN_PROTO_METHOD_NAMES) rides along. - Mechanical sweep, 142 files, comments/prose only — no behavior change.
63 lines
2.3 KiB
TypeScript
63 lines
2.3 KiB
TypeScript
// Per-field width lifts beyond copy/wrap/narrow: 'unknown' destination
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// fields (the static->dyn deep copy), derived->base class fields (the
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// prefix-layout upcast), and function fields whose signatures differ
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// only by clean mechanical conversions. Reads happen after the narrow,
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// where the copy is observationally identical to Node's aliasing.
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// 'unknown' destination field: the source's typed field converts.
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type Env = { v: number; n: number };
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const env: Env = { v: 5, n: 1 };
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const holder: { v: unknown } = env;
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console.log(typeof holder.v, (holder.v as number) + 1);
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// Nested: an array of records reshaping where the element's field is
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// 'unknown' (the dynIn lift riding the per-element copy).
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type Item = { v: number; w: number };
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const items: Item[] = [
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{ v: 1, w: 10 },
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{ v: 2, w: 20 },
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];
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const loose: { v: unknown }[] = items;
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console.log(loose.length, (loose[0]!.v as number) + (loose[1]!.v as number));
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// Derived -> base field: the upcast keeps dynamic dispatch.
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class Base {
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x: number;
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constructor(x: number) {
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this.x = x;
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}
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describe(): string {
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return `base:${this.x}`;
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}
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}
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class Derived extends Base {
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describe(): string {
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return `derived:${this.x}`;
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}
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}
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type HasDerived = { p: Derived; tag: string };
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const hd: HasDerived = { p: new Derived(4), tag: "t" };
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const hb: { p: Base } = hd;
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console.log(hb.p.describe(), hb.p.x);
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// Function field with FEWER parameters than the slot (JS drops extras).
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type Handlers = { f: () => number; name: string };
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const hs: Handlers = { f: () => 7, name: "seven" };
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const slot: { f: (x: number) => number } = hs;
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console.log(slot.f(3));
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// Function field whose RESULT widens into the slot's union arm.
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type Producer = { get: () => number };
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const prod: Producer = { get: () => 42 };
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const optional: { get: () => number | undefined } = prod;
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const got = optional.get();
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console.log(got === undefined ? "none" : got + 1);
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// The lifts compose through nesting: an inner record with an unknown
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// field and a func field, reshaped as part of an outer width copy.
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type Inner = { calc: () => number; note: string };
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type Outer = { inner: Inner; count: number };
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const outer: Outer = { inner: { calc: () => 6, note: "n" }, count: 2 };
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const narrowed: { inner: { calc: (x: number) => number } } = outer;
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console.log(narrowed.inner.calc(99));
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