mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-10-21 05:50:55 +08:00
Chris Tate
94fd361b54
Represent ordinary JavaScript arrays with hole, value, and explicit-undefined states; add sparse side storage and carry missing values through the frontend, native backends, runtime, and Node-facing consumers.
18 lines
677 B
TypeScript
18 lines
677 B
TypeScript
// Optional-call and optional-receiver chains keep their undefined tail while
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// checker-proven guards expose the present string to later builtin calls.
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type Probe = { get?: () => number };
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function probe(present: boolean): Probe {
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return present ? { get: () => 42.5 } : {};
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}
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const hit = probe(true).get?.()?.toString();
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const miss = probe(false).get?.()?.toString();
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console.log(hit, miss);
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console.log(hit !== undefined && /^42/.test(hit));
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console.log(miss !== undefined && /^42/.test(miss));
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function maybeNumber(present: boolean): number | undefined {
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return present ? 1e21 : undefined;
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}
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console.log(maybeNumber(true)?.toString(), maybeNumber(false)?.toString());
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