import type { Nullable } from '@glimmer/interfaces';
import type * as ASTv1 from '../v1/api';
export type NodeCallback<N extends ASTv1.Node> = (node: N, walker: Walker) => void;
export default class Walker {
    order?: unknown | undefined;
    stack: unknown[];
    constructor(order?: unknown | undefined);
    visit<N extends ASTv1.Node>(node: Nullable<N>, visitor: NodeCallback<N>): void;
    children<N extends ASTv1.Node>(node: N & ASTv1.Node, callback: NodeCallback<N & ASTv1.Node>): void;
}