/**
 * AST Visitor
 * Recursive traversal with enter/exit callbacks for validation rules.
 */
import type { ASTNode } from '@rcrsr/rill';
import type { ValidationContext } from './types.js';
/**
 * Visitor pattern interface for AST traversal.
 * Provides enter/exit callbacks invoked before and after visiting children.
 */
export interface RuleVisitor {
    /**
     * Called before visiting node's children.
     * Use for pre-order traversal validation.
     */
    enter(node: ASTNode, context: ValidationContext): void;
    /**
     * Called after visiting node's children.
     * Use for post-order traversal validation.
     */
    exit(node: ASTNode, context: ValidationContext): void;
}
/**
 * Recursively visit AST nodes with enter/exit callbacks.
 * Handles every node type in the ASTNode discriminated union.
 *
 * Traversal order:
 * 1. visitor.enter(node)
 * 2. Recurse into children
 * 3. visitor.exit(node)
 */
export declare function visitNode(node: ASTNode, context: ValidationContext, visitor: RuleVisitor): void;