mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-10-20 05:40:17 +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.
47 lines
1.5 KiB
TypeScript
47 lines
1.5 KiB
TypeScript
// push (including its return value — the new length, JS-exact) and pop.
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// pop on an empty array traps (documented divergence), so lengths are
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// always checked here, as real code must.
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const stack: number[] = [];
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console.log(stack.push(1), stack.push(2), stack.push(3));
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console.log(stack.length);
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console.log(stack.pop(), stack.pop());
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console.log(stack.length, stack[0]);
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// push return value in expressions and conditions
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const xs: number[] = [5];
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const newLen: number = xs.push(6);
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console.log(newLen, newLen === xs.length);
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if (xs.push(7) === 3) {
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console.log("three now");
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}
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// pop into locals; drain a stack with .length in the condition
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const names: string[] = ["ada", "grace", "hopper"];
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const last: string | undefined = names.pop();
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console.log(last ?? "missing", names.length);
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while (names.length > 0) {
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console.log(names.pop() ?? "missing", names.length);
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}
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// booleans round-trip
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const bits: boolean[] = [];
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bits.push(true);
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bits.push(false);
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console.log(bits.pop(), bits.pop(), bits.length);
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// pushing pushes references for nested arrays
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const rows: number[][] = [];
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rows.push([1, 2]);
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rows.push([3]);
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console.log(rows.length, rows[0][0], rows[1][0]);
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const popped: number[] | undefined = rows.pop();
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console.log(popped === undefined ? "missing" : popped[0], rows.length);
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// interleaved push/pop keeps LIFO order
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const log: string[] = [];
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log.push("a");
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log.push("b");
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console.log(log.pop());
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log.push("c");
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console.log(log.pop(), log.pop(), log.length);
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