/*!
 * Copyright 2016 The ANTLR Project. All rights reserved.
 * Licensed under the BSD-3-Clause license. See LICENSE file in the project root for license information.
 */
import { ParseTree } from "./ParseTree";
import { ParseTreeListener } from "./ParseTreeListener";
import { RuleNode } from "./RuleNode";
export declare class ParseTreeWalker {
    /**
     * Performs a walk on the given parse tree starting at the root and going down recursively
     * with depth-first search. On each node, {@link ParseTreeWalker#enterRule} is called before
     * recursively walking down into child nodes, then
     * {@link ParseTreeWalker#exitRule} is called after the recursive call to wind up.
     * @param listener The listener used by the walker to process grammar rules
     * @param t The parse tree to be walked on
     */
    walk<T extends ParseTreeListener>(listener: T, t: ParseTree): void;
    /**
     * Enters a grammar rule by first triggering the generic event {@link ParseTreeListener#enterEveryRule}
     * then by triggering the event specific to the given parse tree node
     * @param listener The listener responding to the trigger events
     * @param r The grammar rule containing the rule context
     */
    protected enterRule(listener: ParseTreeListener, r: RuleNode): void;
    /**
     * Exits a grammar rule by first triggering the event specific to the given parse tree node
     * then by triggering the generic event {@link ParseTreeListener#exitEveryRule}
     * @param listener The listener responding to the trigger events
     * @param r The grammar rule containing the rule context
     */
    protected exitRule(listener: ParseTreeListener, r: RuleNode): void;
}
export declare namespace ParseTreeWalker {
    const DEFAULT: ParseTreeWalker;
}