import { Reference } from 'regjsparser';
import { MyFeatures, MyRootNode } from './parse';
export type DowngradePatternConfig = Readonly<{
    /**
     * The regex pattern.
     */
    pattern: string;
    /**
     * Set to `true` to enable unicode mode.
     */
    unicode: boolean;
}>;
export type DowngradedRegexPattern = Readonly<{
    /**
     * Offsets to groups which should be considered atomic.
     *
     * E.g. `(?=(a))\1` => `(?=(a))(?:a)` with atomic group offset 7.
     */
    atomicGroupOffsets: ReadonlySet<number>;
    /**
     * The downgraded pattern.
     */
    pattern: string;
}>;
export type RawWithoutCapturingGroupsOrLookaheads = Readonly<{
    referencesWithOffset: ReadonlyMap<Reference<MyFeatures>, number>;
    result: string;
}>;
export declare function isMissingStartAnchor(rootNode: MyRootNode): boolean;
export declare function getRawWithoutCapturingGroupsOrLookaheads(rootNode: MyRootNode): RawWithoutCapturingGroupsOrLookaheads;
/**
 * Downgrade the provided pattern if needed so that it is supported for checking.
 *
 * A downgraded pattern may introduce false positives.
 *
 * This does the following:
 * - If the pattern contains a reference to a group that lives in a positive lookahead,
 *   the reference will be replaced with a non-capturing group that contains referenced group.
 * - If the pattern contains a reference to a group that is a non-finite size,
 *   the reference will be replaced with a non-capturing group that contains the referenced group.
 * - If the pattern does not contain a start anchor then `[^]*` will be prepended, and the remainder
 *   wrapped in a none capturing group if needed.
 */
export declare function downgradePattern({ pattern, unicode, }: DowngradePatternConfig): DowngradedRegexPattern;