mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-10-26 06:34:20 +08:00
Chris Tate
057ac2cea2
- 2530-2535 and 2541 lock in the destructuring forms the static tier already compiled but the corpus never pinned: object/array/tuple declarations (renames, defaults, holes, nesting, fresh rest tails), the options-object parameter pattern (element and whole-pattern defaults, tuple/rest parameter patterns), for-of heads (containers, defaults, rest, existing bindings), object rest freshness and key order, assignment basics (swaps, chains, expression value), and evaluation order (RHS once, elements left to right, lazy defaults that see earlier bindings). - All byte-identical against Node under both backends, and each reports 100% static coverage.
55 lines
1.3 KiB
TypeScript
55 lines
1.3 KiB
TypeScript
// Destructuring ASSIGNMENT to existing bindings: object shorthand and
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// renames, array positions, swaps, defaults, rest, empty patterns, and
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// the assignment-expression VALUE (the RHS, enabling chains).
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const src = { a: 1, b: 2, c: 3 };
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let a = 0;
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let b = 0;
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({ a, b } = src);
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console.log(a, b);
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let renamed = 0;
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({ c: renamed } = src);
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console.log(renamed);
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let m = 1;
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let n = 2;
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[m, n] = [n, m];
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console.log(m, n);
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const nums = [10, 20, 30, 40];
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let first = 0;
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let rest: number[] = [];
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[first, ...rest] = nums;
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console.log(first, rest.join(","));
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// Defaults in assignment position — undefined fires them, values don't.
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const opt: { p?: number; q?: number } = { q: 5 };
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let p = -1;
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let q = -1;
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({ p = 77, q = 88 } = opt);
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console.log(p, q);
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// Array defaults carry the bounds test.
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let d0 = 0;
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let d1 = 0;
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const bounds: number[] = [9];
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[d0 = -1, d1 = -2] = bounds;
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console.log(d0, d1);
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// Object rest in assignment position.
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let restObj: { b: number; c: number } = { b: 0, c: 0 };
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({ a, ...restObj } = src);
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console.log(a, JSON.stringify(restObj));
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// The assignment expression's VALUE is the RHS: chains and reads work.
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let x = 0;
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let y = 0;
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const source: { a: number; b: number } = { a: 6, b: 7 };
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const out = ({ a: x } = { b: y } = source);
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console.log(x, y, out.a + out.b);
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// Empty patterns validate and nothing else.
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({} = src);
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[] = nums;
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console.log("done");
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