/**
 * .what = computes a unique temp directory name with timestamp prefix and slug
 * .why = timestamp prefix enables age-based cleanup without stat calls
 *        slug helps debuggers identify which test created the directory
 *        run stamp lets a run reclaim exactly the dirs it made, and no peer's
 *
 * .note = 🔴 the run slot is ALWAYS emitted — a run id, or `_` when no run minted
 *         this. every name therefore has ONE arity, which is what lets the shared
 *         grammar pin the slot and read the run out of a match group rather than a
 *         positional probe. an optional slot would let a slug occupy the run's
 *         position and read back AS a run, which this function would then have to
 *         reject the consumer's own slug to prevent. one arity makes the collision
 *         unreachable, so a slug may be any text at all — `_` included
 *
 * .note = the slot sits INSIDE the free-text segment the age gate's parse takes as
 *         `.+`, so that parse holds by construction. this function asserts the
 *         round trip on its own output, before any dir is made
 *
 * @example
 * computeTempDirName({ slug: 'my-test', run: null })
 * // => '2026-01-19T12-34-56.789Z._.my-test.a1b2c3d4'
 *
 * @example
 * computeTempDirName({ slug: 'my-test', run: 'r7f3a91c2' })
 * // => '2026-01-19T12-34-56.789Z.r7f3a91c2.my-test.a1b2c3d4'
 */
export declare const computeTempDirName: (input: {
    slug: string;
    /**
     * the run that mints this name, or null when no run is enhooked
     *
     * .note = REQUIRED, and `null` is how a caller says "unstamped". an OPTIONAL run
     *         makes a forgotten stamp type-legal, so a new call site can omit it and
     *         leave its dirs unreclaimable under a run whose count reads zero.
     *         required forces every site to state which it means
     */
    run: string | null;
}) => string;
/**
 * .what = reads the timestamp out of a temp directory name
 * .why = enables age calculation for prune decisions
 *
 * .note = `as*`, never `parse*` — a cast from one shape to another is a transformer,
 *         and `as` is this repo's ONE sanctioned cast prefix. it groups with
 *         `asTempDirRun` under one autocomplete stem besides
 */
export declare const asTempDirTimestamp: (input: {
    dirName: string;
}) => Date | null;
/**
 * .what = reads the run stamp out of a temp directory name
 * .why = the reclaim matches on it, so a run reaps its own dirs and no peer's
 *
 * @returns the run id, or null when no run minted the dir
 *
 * .note = 🔴 it reads the run out of the shared grammar's SECOND GROUP, never by
 *         `split('.')` and an index. a positional form must shape-test what it
 *         finds to decide whether it is a stamp or a slug, which makes a run-shaped
 *         slug indistinguishable from a run. one match yields both the timestamp
 *         and the run, so the two facts cannot disagree
 *
 * @example
 * asTempDirRun({ dirName: '2026-01-19T12-34-56.789Z.r7f3a91c2.my-test.a1b2c3d4' });
 * // => 'r7f3a91c2'
 *
 * @example
 * // the run slot holds `_`, so no run minted it
 * asTempDirRun({ dirName: '2026-01-19T12-34-56.789Z._.my-test.a1b2c3d4' });
 * // => null
 *
 * @example
 * // a legacy name, minted before the slot existed — no run either way
 * asTempDirRun({ dirName: '2026-01-19T12-34-56.789Z.my-test.a1b2c3d4' });
 * // => null
 *
 * @example
 * // a SLUG shaped like a run id is no longer read as one — it cannot occupy the
 * // run's position, because the run's position is always filled
 * asTempDirRun({ dirName: '2026-01-19T12-34-56.789Z._.r7f3a91c2.a1b2c3d4' });
 * // => null
 */
export declare const asTempDirRun: (input: {
    dirName: string;
}) => string | null;