// $Id: Instruction.java,v 1.5 1999/10/06 03:40:00 deberg Exp $package java6035.tools.IR;/** * Instruction class represents a statement or instruction in your program. * There are several forms of instructions in this package: * * <PRE> * assignment instrs         SimpleInstr class * expression statement      SimpleInstr class * branch instrs             BranchInstr class * label instr               LabelInstr  class * return instr              ReturnInstr class * </PRE> */public abstract class Instruction extends TreeNode {    public String PPrint(int indent, boolean recursive)    {        String output = new String();        for(int i=0;i<indent;i++) output += " ";        output += "PPrint of instructions not supported\n";        return output;    }}