export interface UndoManager {
    push<U, R>(undo: UndoItem<U, R>): void;
    undo(): void;
    redo(): void;
}
export type UndoItem<UndoState = unknown, RedoState = unknown> = [
    state: UndoState,
    undo: UndoCallback<UndoState, RedoState>
];
export type UndoCallback<UndoState = unknown, RedoState = unknown> = (state: UndoState) => RedoItem<RedoState, UndoState>;
export type RedoItem<RedoState = unknown, UndoState = unknown> = [
    state: RedoState,
    redo: RedoCallback<RedoState, UndoState>
];
export type RedoCallback<RedoState = unknown, UndoState = unknown> = (state: RedoState) => UndoItem<UndoState, RedoState>;