import type { Logger } from './logger';
import type { Experiment, Variant } from './store';
/**
 * Decide between all experiments in a repeatable way. This function works on the presumption that
 * only one experiment can be active for any device at any given time.
 *
 * @param experiments The experiments being decided between
 * @param deviceId Identifier allowing for repeatable decisions
 */
export declare const decideExperiment: (experiments: Experiment[], deviceId: string, logger: Logger) => Experiment | undefined;
/**
 * Decide between variants in a repeatable way.
 *
 * @param variants The variants being decided between
 * @param deviceId Identifier allowing for repeatable decisions
 */
export declare const decideVariant: (variants: Variant[], deviceId: string, logger: Logger) => Variant | undefined;
/**
 * Returns the index of the probability matching the input value. If the sum of probabilities does
 * not add up to 1 than this function will return -1 indicating that none of the given probabilities
 * was selected.
 *
 * @param probabilities Array of probabilities who's sum is between 0 (exclusive) and 1 (inclusive).
 * @param value The value who's index is being determined. Float between 0 (inclusive) and 1 (exclusive).
 *
 * @example
 * // always returns 0
 * indexFromProbability([1.0], 0.8)
 *
 * @example
 * // returns 1
 * indexFromProbability([0.1, 0.7, 0.2], 0.2)
 *
 * @example
 * // returns 2
 * indexFromProbability([0.1, 0.7, 0.2], 0.81)
 *
 * @example
 * // returns -1
 * indexFromProbability([0.1, 0.4], 0.63)
 */
export declare const indexOfProbability: (probabilities: number[], value: number, logger: Logger) => number;
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