Save and resume a stream

Count source draws

counted is a native source with seed, draw count and position. Save its position after the work you want to resume. The count is source draws, not calls to a high-level recipe; for example a normal draw consumes two.

import { counted, fromJSON, randomAt, toJSON, toText } from "@johnmorrisdotca/tane";

const random = counted(42);
random(); random(); random();
const position = random.position();
const restored = fromJSON(toJSON(position));
if (restored === null) throw new Error("Invalid saved position");
console.log(position.draws, toText(position));
console.log(random(), randomAt(restored.seed, restored.draws)());

3 tane:1:42:3
0.6697340414393693 0.6697340414393693

Choose a representation

JSON includes format, algorithm, position and derived state; the reader checks their consistency. Text is a compact position line. CSV exports upcoming values and resulting states. randomAt resumes and stateAt computes the generator state without replaying every prior draw.

Refuse a bad position

fromJSON and fromText return null for invalid or unsupported records. Check the result before resuming. The host chooses storage; the package performs no upload. The specification preserves the algorithm and format details.