1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * See LICENSE.txt included in this distribution for the specific 9 * language governing permissions and limitations under the License. 10 * 11 * When distributing Covered Code, include this CDDL HEADER in each 12 * file and include the License file at LICENSE.txt. 13 * If applicable, add the following below this CDDL HEADER, with the 14 * fields enclosed by brackets "[]" replaced with your own identifying 15 * information: Portions Copyright [yyyy] [name of copyright owner] 16 * 17 * CDDL HEADER END 18 */ 19 20 /* 21 * Copyright (c) 2009, 2018, Oracle and/or its affiliates. All rights reserved. 22 * Portions Copyright (c) 2011, Jens Elkner. 23 * Portions Copyright (c) 2017, 2020, Chris Fraire <cfraire@me.com>. 24 */ 25 package org.opengrok.indexer.analysis; 26 27 import java.io.IOException; 28 29 /** 30 * Represents an API for an extension of {@link JFlexLexer} that needs to track 31 * a state stack. 32 */ 33 public interface JFlexStackingLexer extends JFlexLexer { 34 35 /** 36 * Saves current {@link #yystate()} to stack, and enters the specified 37 * {@code newState} with {@link #yybegin(int)}. 38 * @param newState state id 39 */ yypush(int newState)40 void yypush(int newState); 41 42 /** 43 * Pops the last state from the stack, and enters the state with 44 * {@link #yybegin(int)}. 45 * @throws IOException if any error occurs while effecting the pop 46 */ yypop()47 void yypop() throws IOException; 48 49 /** 50 * Gets the yychar value. 51 */ getYYCHAR()52 long getYYCHAR(); 53 54 /** 55 * Gets the YYEOF value. 56 */ getYYEOF()57 int getYYEOF(); 58 59 /** 60 * Gets the line number. 61 */ getLineNumber()62 int getLineNumber(); 63 64 /** 65 * Tests if the instance's state stack is empty. 66 * @return {@code true} if the stack contains no items; {@code false} 67 * otherwise. 68 */ emptyStack()69 boolean emptyStack(); 70 } 71