/** The minimal node shape the projection reads; the adapters' own node types are supersets of it. */
export interface TreeColumnNode {
    value: string;
    disabled?: boolean | undefined;
    /** Declares a branch whose children have not loaded yet, so its column exists while still empty. */
    hasChildren?: boolean | undefined;
    children?: readonly TreeColumnNode[] | undefined;
}
/** One rendered column: the sibling set at a single depth. */
export interface TreeColumn {
    /** The branch whose children this column lists, or `null` for the root column. */
    parent: string | null;
    /** The column's nodes in collection order; empty while a lazy branch is still loading. */
    nodes: readonly TreeColumnNode[];
}
/**
 * The columns showing for an expanded set: the roots, then one column per expanded branch along a single open path.
 *
 * Columns are a chain, so at most one branch per depth can be open. An
 * `expanded` set naming two branches at the same depth is not an error: the
 * first in collection order wins and the rest are ignored, which keeps the
 * projection total and lets a consumer hand the same `expanded` array to
 * either layout.
 *
 * @param collection the root nodes, each carrying its own children
 * @param expanded every expanded node's value, in any order
 * @returns the columns left to right; always at least the root column
 */
export declare function treeColumns(collection: readonly TreeColumnNode[], expanded: Iterable<string>): TreeColumn[];
/**
 * The chain of values from the root down to `value`, inclusive, or empty when the collection does not hold it.
 *
 * This is the expanded set that opens `value`'s own column: passing it to
 * {@link treeColumns} shows every ancestor's column and closes every branch off
 * the path. Dropping its last entry is the set that closes `value`'s column
 * instead, which is what moving back a column needs.
 *
 * @param collection the root nodes, each carrying its own children
 * @param value the node to reach
 */
export declare function pathTo(collection: readonly TreeColumnNode[], value: string): string[];
/**
 * The index of the column holding `value`, or `-1` when no showing column does.
 *
 * @param columns the projection {@link treeColumns} returned
 * @param value the node to locate
 */
export declare function columnIndexOf(columns: readonly TreeColumn[], value: string): number;