simpletron.java

来自「一个用JAVA做的」· Java 代码 · 共 229 行

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package srtpv02;
import java.io.*;
import java.util.*;
import java.util.regex.Pattern;
/**
 *
 * @author Administrator
 */
public class Simpletron {
    private static Simpletron instance;
    
    private Simpletron() {
        System.out.println("Welcome to Simpletron");
    }
    
    public static Simpletron GetInstance() {
        if( instance == null ) {
            instance = new Simpletron();
        }
        
        return instance;
    }

    public void run() throws Exception {
        readCode(new Scanner(System.in));
        execute();
    }
    
    public void run (String fileName) throws FileNotFoundException ,Exception {
        readCode(new Scanner(new File(fileName + ".code")));
        readMemory(new Scanner(new File(fileName + ".mem")));
        readSMemory(new Scanner(new File(fileName + ".smem")));
        execute();
    }
    
    private void readCode(Scanner sc) throws Exception {
        for(int count=0;count<100;++count) {
            codeMemory[count] = sc.nextInt();
        }
    }

    private void readMemory(Scanner sc) throws Exception {
        for(int count=0;count<100;++count) {
            dataMemory[count] = sc.nextInt();
        }
    }

    private void readSMemory(Scanner sc) throws Exception {
        sc.useDelimiter(Pattern.compile("\\n"));
        for(int count=0;count<50;++count) {
            stringMemory[count] = sc.next();
        }
    }
    
    private void execute() throws Exception {
        int instructionRegister;
        int codeCount = 0;
        int stringCount = 0;
        int operationCode = 0;
        int operand = 0;
        int accumulator = 0;             //作为数据的寄存器
        String sAccumulator = null;      //作为字符串的寄存器
        boolean flag = true;
        Stack<Integer> nextIP = new Stack<Integer>();
        BufferedReader stdin = new BufferedReader(
                new InputStreamReader(System.in));
        while(flag) {
            instructionRegister = codeMemory[codeCount];
            operationCode = instructionRegister / 100;
            operand = instructionRegister % 100;
            
            switch (operationCode) {
                case READ:
                    String s = stdin.readLine();
                    dataMemory[operand] = Integer.parseInt(s);
                    break;
                case READSTRING:
                    s = stdin.readLine();
                    stringMemory[operand] = s;
                    break;
                case STORE:
                    dataMemory[operand] = accumulator;
                    break;
                case STORESTRING:
                    stringMemory[operand] = sAccumulator;
                    break;
                case WRITE:
                    System.out.println(dataMemory[operand]);
                    break;
                case WRITESTRING:
                    System.out.println(stringMemory[operand]);
                    break;
                case LOAD:
                    accumulator = dataMemory[operand];
                    break;
                case LOADSTRING:
                    sAccumulator = stringMemory[operand];
                    break;
                case ADD:
                    accumulator += dataMemory[operand];
                    break;
                case SUBTRACT:
                    accumulator -= dataMemory[operand];
                    break;
                case DIVIDE:
                    accumulator /= dataMemory[operand];
                    break;
                case MULTIPLY:
                    accumulator *= dataMemory[operand];
                    break;
                case MOD:
                    accumulator %= dataMemory[operand];
                    break;
                case POWER:
                    accumulator = (int)Math.pow(accumulator, dataMemory[operand]);
                    break;
                case BRANCH:
                    codeCount = operand;
                    continue;
                case BRANCHNEG:
                    if( accumulator < 0 ) {
                        codeCount = operand;
                        continue;
                    } else 
                        break;
                case BRANCHNEGANDEQU:
                    if( accumulator <= 0 ) {
                        codeCount = operand;
                        continue;
                    } else
                        break;
                case BRANCHPOSANDEQU:
                    if( accumulator >= 0 ) {
                        codeCount = operand;
                        continue;
                    } else
                        break;
                case BRANCHPOS:
                    if( accumulator > 0 ) {
                        codeCount = operand;
                        continue;
                    } else
                        break;
                case BRANCHZERO:
                    if( accumulator == 0 ) {
                        codeCount = operand;
                        continue;
                    } else 
                        break;
                case BRANCHNOTEQU:
                    if( accumulator != 0 ) {
                        codeCount = operand;
                        continue;
                    } else
                        break;
                case HALT:
                    flag = false;
                    break;
                case GOSUB:
                    nextIP.push(codeCount + 1);
                    codeCount = operand;
                    continue;
                case RETURN:
                    codeCount = nextIP.pop();
                    continue;
                default:
                    throw new Exception("语法错误:" + instructionRegister);
            }
            
            ++codeCount;
            
        }
    }
    private int[] dataMemory = new int[100];
    private int[] codeMemory = new int[100];
    private String[] stringMemory = new String[50];
    private static final int READ = 10;             //读取到指定的内存单元
    private static final int WRITE = 11;            //写到屏幕
    private static final int READSTRING = 12;
    private static final int WRITESTRING = 13;
    private static final int LOAD = 20;             //将内存单元的内容装入累加器
    private static final int STORE = 21;            //将累加器中内容放回指定内存单元
    private static final int LOADSTRING = 22;
    private static final int STORESTRING = 23;
    private static final int ADD = 30;
    private static final int SUBTRACT = 31;
    private static final int DIVIDE = 32;
    private static final int MULTIPLY = 33;
    private static final int MOD = 34;
    private static final int POWER = 35;
    private static final int BRANCH = 40;
    private static final int BRANCHNEG = 41;
    private static final int BRANCHZERO = 42;
    private static final int BRANCHPOSANDEQU = 44;
    private static final int BRANCHNEGANDEQU = 45;
    private static final int BRANCHPOS = 43;
    private static final int BRANCHNOTEQU = 46;
    private static final int HALT = 80;
    private static final int GOSUB = 52;
    private static final int RETURN = 53;
}