mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-11-02 07:43:42 +08:00
Chris Tate
c54c4e1d2a
- Module globals of type number join the whole-program int32 fixpoint as `global:` candidates, starting non-negative. A candidate needs its module initializer to assign it at the top level (its declaration), and no write by `++`/`--`, for-of or catch; every assignment must evaluate to an int32 under the current facts (an integer literal counts in any function), and a write that may be negative keeps only the int32 fact. - Reads take the proven range through IntegerSlotFacts.locals, so a generator state reduced by a remainder (`seed = (seed * a + c) % m`) takes unsigned integer remainders without the -0 select.
72 lines
1.7 KiB
TypeScript
72 lines
1.7 KiB
TypeScript
// Module-level number state written from several functions: a generator
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// state reduced by a remainder, a counter that goes negative, a value that
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// becomes a fraction, writes from a closure and an async function, and a
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// read before the declaration runs.
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function early(): number {
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return marker + 1;
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}
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try {
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console.log("early", early());
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} catch (error) {
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console.log("early", (error as Error).name);
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}
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let marker = 5;
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let seed = 42;
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let balance = 10;
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let ratio = 3;
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let ticks = 0;
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function next(): number {
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seed = (seed * 3877 + 29573) % 139968;
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return seed;
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}
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function fill(buffer: Float64Array): void {
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let l = seed;
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for (let k = 0; k < buffer.length; k++) {
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l = (l * 3877 + 29573) % 139968;
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buffer[k] = l / 139968;
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}
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seed = l;
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}
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function spend(amount: number): number {
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balance = (balance & 1023) - amount;
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return balance;
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}
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function halve(): number {
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ratio = ratio / 2;
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return ratio;
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}
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const tick = (): number => {
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ticks = (ticks + 7) % 10;
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return ticks;
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};
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async function later(): Promise<number> {
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await Promise.resolve();
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ticks = 9;
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return ticks;
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}
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const buffer = new Float64Array(5);
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console.log("next", next(), next(), next());
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fill(buffer);
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let shown = "";
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for (const v of buffer) shown += ` ${v.toFixed(6)}`;
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console.log("fill", shown, seed);
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seed = 2147483647;
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console.log("large", next(), next());
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seed = 0;
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console.log("zero", next());
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console.log("spend", spend(4), spend(30), spend(-2000), spend(5));
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console.log("halve", halve(), halve(), ratio * 4);
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console.log("tick", tick(), tick(), tick(), ticks);
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console.log("later", await later(), ticks, tick());
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marker = marker * 3;
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console.log("marker", early(), marker);
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