/**
 * Generates a hashing object that can be used to create hashes of a
 * token string. It is based on the rolling hash used in the
 * Rabin-Karp string matching algorithm, but without the rolling
 * property.
 *
 * The hash base is chosen to be different than the one used in
 * RollingHash as to not create collisions with similar subsequent
 * tokens (e.g. hash(['abc'] should not equal hash(['a', 'b', 'c'])).
 */
export declare class TokenHash {
    /**
     * The modulus used in the hash calculation.
     *
     * Since we want to be able to take the product of two hashes, the product of
     * two hashes, the modulus multiplied by itself should not have more than the
     * available amount of bits of precision.
     *
     * Javascript has 53-bit precision numbers (doubles) so we pick the largest
     * prime number with 26 bits.
     */
    readonly mod: number;
    /**
     * The base (or radix) used in the hash calculation.
     *
     * We want that even small tokens use as much bits as possible. Because we
     * assume the input token characters will mostly be less than 128, we pick
     * our base such that multiplying with an input character use as much bits
     * as possible.
     *
     * Hence this is the largest prime number such that 127 * base < mod.
     */
    readonly base: number;
    hashToken(token: string): number;
}
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