/**
 * Folded spelling as a case-insensitive, normalization-insensitive volume sees
 * it. `toLowerCase()` alone is not Unicode case folding: final sigma `ς`
 * stays `ς` while `Σ` lowers to `σ`, yet APFS and NTFS treat all three as one
 * name. Mapping each code point through its single-code-point upper case
 * first (simple case folding) closes those gaps. Expanding upper cases such
 * as `ß` -> `SS` are left alone: filesystems use simple, not full, folding.
 */
export declare function foldVaultKey(key: string): string;
export interface CaseAliasTracker {
    /** Record a key the remote LIST holds (a live object). */
    observeRemote(remoteKey: string): void;
    /**
     * Stop observing and return the aliased keys. Drops the candidate map and
     * the membership callback so they are not retained through the transfer
     * phase; the plan keeps only this (normally tiny) set.
     */
    finish(): ReadonlySet<string>;
}
/**
 * @param candidateKeys keys the executors may delete (journal rows, tombstoned keys)
 * @param hasCandidate  exact-membership test over the same keys, used for a
 *                      remote key's folded spelling so all-lower-case
 *                      candidates need no map entry
 */
export declare function createCaseAliasTracker(candidateKeys: Iterable<string>, hasCandidate: (key: string) => boolean): CaseAliasTracker;
/**
 * Return the on-disk spelling when a live path differs from `key` only by
 * filesystem case folding. This also supports injected folding behavior in
 * tests on case-sensitive hosts.
 */
export declare function findCaseFoldedLocalKey(root: string, key: string): string | null;
/**
 * Whether lookups inside `dir` fold case. Takes an existing child whose name
 * has letters and checks that its case-flipped spelling, looked up in the same
 * directory, resolves to the same inode. Probing inside `dir` (not `dir` in
 * its parent) measures the filesystem that stores the synced files even when
 * `dir` is itself a mount point. An empty directory, a directory with no
 * letter-bearing names, or any error reads as "does not fold", which keeps
 * today's delete behaviour; with no children there is nothing to delete.
 */
export declare function directoryFoldsCase(dir: string): boolean;
//# sourceMappingURL=case-alias.d.ts.map