mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-11-08 08:44:37 +08:00
Chris Tate
2c7b67c5aa
- The jsval pass also promotes dyn module globals to jsval globals when only dynamic-tier functions read and write them and the boxing their writes save outweighs the boxing their reads add, the measure locals use. `checksum += f(x)` in a top-level loop no longer allocates a number cell per update. - A class dispatch helper that calls a method returning `this` on every path calls a copy of the method that returns nothing and answers its own receiver, the capsule of the same instance at its exact class, so the call boxes nothing.
54 lines
1.4 KiB
JavaScript
54 lines
1.4 KiB
JavaScript
// Module-level `let` bindings that untyped code updates in loops: numbers,
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// then values of other kinds, read by functions declared before and after.
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function readTotal() {
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return total;
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}
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let total = 0;
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let label = "n";
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let mixed = 1;
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let big = 10n;
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let counter = 0;
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var hoisted;
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function bump(n) {
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return n * 2 + 1;
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}
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for (let i = 0; i < 1000; i++) {
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total += bump(i);
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label += i % 10 === 0 ? i : "";
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mixed = mixed * 1.5 + i;
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big += BigInt(i);
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counter++;
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}
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console.log(total, readTotal(), label.length, mixed, big, counter);
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total = total / 0;
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console.log(total, readTotal());
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total = -0;
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console.log(Object.is(total, -0), 1 / total);
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total = NaN;
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console.log(total === total, String(total));
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mixed = "text";
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mixed += 5;
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console.log(mixed, typeof mixed);
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mixed = { value: 3 };
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mixed.value += 4;
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console.log(mixed.value, JSON.stringify(mixed));
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mixed = undefined;
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console.log(mixed, typeof mixed, mixed ?? "fallback");
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mixed = null;
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console.log(mixed === null, `${mixed}`);
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hoisted = 0;
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for (let i = 0; i < 10; i++) hoisted += i * 0.1;
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console.log(hoisted);
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const add = (n) => {
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total = (Number.isNaN(total) ? 0 : total) + n;
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return total;
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};
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for (let i = 0; i < 5; i++) add(i);
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console.log(total, readTotal());
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let product = 1;
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for (let i = 1; i <= 25; i++) product *= i;
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console.log(product, product > Number.MAX_SAFE_INTEGER);
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let text = 0;
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for (let i = 0; i < 3; i++) text = text + "" + i;
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console.log(text, typeof text);
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