1 /* 2 * StackFrame.java 3 * 4 * Copyright (C) 2009 Mark Evenson 5 * $Id$ 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2 10 * of the License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 20 * 21 * As a special exception, the copyright holders of this library give you 22 * permission to link this library with independent modules to produce an 23 * executable, regardless of the license terms of these independent 24 * modules, and to copy and distribute the resulting executable under 25 * terms of your choice, provided that you also meet, for each linked 26 * independent module, the terms and conditions of the license of that 27 * module. An independent module is a module which is not derived from 28 * or based on this library. If you modify this library, you may extend 29 * this exception to your version of the library, but you are not 30 * obligated to do so. If you do not wish to do so, delete this 31 * exception statement from your version. 32 */ 33 34 package org.armedbear.lisp; 35 36 import static org.armedbear.lisp.Lisp.*; 37 38 public abstract class StackFrame 39 extends LispObject 40 { 41 @Override typep(LispObject typeSpecifier)42 public LispObject typep(LispObject typeSpecifier) 43 44 { 45 if (typeSpecifier == Symbol.STACK_FRAME) 46 return T; 47 if (typeSpecifier == BuiltInClass.STACK_FRAME) 48 return T; 49 return super.typep(typeSpecifier); 50 } 51 52 StackFrame next; 53 Environment env = null; 54 setNext(StackFrame nextFrame)55 void setNext(StackFrame nextFrame) { 56 this.next = nextFrame; 57 } getNext()58 StackFrame getNext() { 59 return this.next; 60 } 61 62 /** Sets the applicable environment for this stack frame to 'env', 63 * returning the last value. 64 */ setEnv(Environment env)65 public Environment setEnv(Environment env) { 66 Environment e = this.env; 67 this.env = env; 68 return e; 69 } 70 /** Gets the current lexical environment of this stack frame. */ getEnv()71 public Environment getEnv() { 72 return env; 73 } toLispList()74 public abstract LispObject toLispList(); toLispString()75 public abstract SimpleString toLispString(); 76 } 77