/**
 * Seeded, deterministic PRNG (mulberry32).
 *
 * A given seed must always reproduce the exact same world, so consumers ban
 * `Math.random` by lint outside this file.
 *
 * ## Why there are two interfaces
 *
 * The four repos that had grown their own copy did not agree on shape:
 * konbini-67 used mutable state plus free functions (`nextFloat(rng)`),
 * while sims3-clone and europe-county-map returned an object of closures
 * (`rng.next()` / `rng.float()`). Both are exported here rather than
 * reconciled into one, because the *sequence* is the contract: these repos
 * have seeded tests and "same seed -> identical world" guarantees, and
 * changing how many times a helper advances the generator silently changes
 * every generated world. A shared package that quietly re-rolled saved
 * worlds would be worse than the duplication it replaced.
 *
 * The generator core is identical in both, so a given seed produces the same
 * float sequence whichever interface you use -- verified in the tests.
 *
 * Note `int` is inclusive of both bounds, matching sims3-clone and
 * europe-county-map. konbini-67's local helper took a single *exclusive*
 * max; it maps to `int(rng, 0, max - 1)`.
 */
/** Mutable state for a mulberry32 generator. */
export interface Rng {
    /** Internal 32-bit state. Advanced by every draw. */
    s: number;
}
/** Creates mutable generator state from a seed. */
export declare const createRng: (seed: number) => Rng;
/**
 * Deterministic float in [0, 1). Advances the generator.
 *
 * This is the mulberry32 core; every other helper here is defined in terms
 * of it, so they all consume exactly one step per call.
 */
export declare const nextFloat: (rng: Rng) => number;
/** Deterministic integer in [minInclusive, maxInclusive]. One step. */
export declare const nextInt: (rng: Rng, minInclusive: number, maxInclusive: number) => number;
/** True with the given probability in [0, 1]. One step. */
export declare const nextChance: (rng: Rng, probability: number) => boolean;
/**
 * Deterministic pick from a non-empty tuple. One step.
 *
 * Iterates rather than indexing: under `noUncheckedIndexedAccess` an index
 * read is `T | undefined`, and the undefined arm is unreachable here, so it
 * could never be covered by a test.
 */
export declare const pick: <T>(rng: Rng, items: readonly [T, ...T[]]) => T;
/**
 * The closure-style interface, for consumers that pass an `Rng` object
 * around rather than threading mutable state through free functions.
 */
export interface SeededRng {
    /** True with the given probability in [0, 1]. */
    chance: (probability: number) => boolean;
    /** Uniform float in [0, 1). */
    float: () => number;
    /** Uniform integer in [minInclusive, maxInclusive]. */
    int: (minInclusive: number, maxInclusive: number) => number;
    /** Uniform element of a non-empty array. */
    pick: <T>(items: readonly T[]) => T;
}
/**
 * Creates a {@link SeededRng} over the same mulberry32 core.
 *
 * `pick` throws on an empty array rather than returning `undefined`: the
 * callers all treat their input as non-empty, and a silent `undefined`
 * propagates into generated data where it is far harder to trace.
 */
export declare const createSeededRng: (seed: number) => SeededRng;
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