编译原理——赋值语句与简单表达式（五）

语法。

Syntax.java：

package per.eyuan.compile;import per.eyuan.util.Action;import per.eyuan.util.ConstantTable;import per.eyuan.util.FourItem;import per.eyuan.util.FourItemStack;import per.eyuan.util.GoTo;import per.eyuan.util.IdentifierTable;import per.eyuan.util.MyStack;import per.eyuan.util.TemporaryTable;import per.eyuan.util.TwoItemStack;public class Syntax {IdentifierTable idt;//标志符表ConstantTable cont;//常数表TemporaryTable tt;//临时变量表TwoItemStack tis;//二元式栈FourItemStack fis;//四元式栈MyStack msStatu=new MyStack();//状态栈，存放状态MyStack msSymble=new MyStack();//符号栈，存放符号MyStack msSmtm=new MyStack();//语义栈Action act=new Action();//Action表GoTo gt=new GoTo();//GoTo表String action;//动作boolean succ=false;//是否接受，分析成功String statu="";//当前动作时的状态栈内容String symble="";//符号栈内容String state="";//语句String semanteme="";//语义String syntax[]={"A->id=E;","E->E+T","E->T","T->T*F","T->F","F->(E)","F->id"};String synL[]={"A","E","E","T","T","F","F"};String synR[][]={{"id","=","E",";"},{"E","+","T"},{"T"},{"T","*","F"},{"F"},{"(","E",")"},{"id"}};String vnType;//非终结符的“类型”int til;//传递来的二元式的长度int Ep,E1p,Tp,T1p,Fp;//非终结符指向的标志符入口public Syntax() {super();init();}public void init(){//状态栈和符号栈初始化msStatu.push("0");//状态msSymble.push("#");//符号msSmtm.push("_");//语义}public void analyse(){System.out.println("状态栈\t\t符号栈\t\t语义\t\t输入串\t\t\t动作说明");while(!succ){//获取状态栈和语句栈栈顶，查询Action表act.setTable(msStatu.getTop(), tis.getTop().getCategory());//获取Action表返回的动作，并作处理action=act.getAction();perform(action);}}public void acc(){fis.push(new FourItem("=","T"+Ep,"_",idt.getId(Integer.parseInt(tis.getHole()[til-1].getInside())).getName()));int i=0;for(;i<cont.getCount();i++)if(cont.getAllConstant()[i].getValue().equals(tt.getTemp(Ep).getValue())){//常数表中已有该常数//id指向该常数idt.getId(Integer.parseInt(tis.getHole()[til-1].getInside())).setValue(i);i=cont.getCount();}if(i==cont.getCount()){//常数表中没有该常数//将常数加入常数表cont.addConstant("int",tt.getTemp(Ep).getValue());//id指向新增常数idt.getId(Integer.parseInt(tis.getHole()[til-1].getInside())).setValue(cont.getCount()-1);}}public void perform(String action){//出错String actNum="";//规约或者移进是的数字for(int i=1;i<action.length();i++)actNum+=action.charAt(i);if(action.equals("err")){error();}//接受else if(action.equals("acc")){this.succ=true;output(-1);acc();}//移进//移进时，状态入栈，符号入栈，语义入栈，二元式“出栈”else if(action.charAt(0)=='s'){int x=Integer.parseInt(actNum);output(x);//输出动作说明等msStatu.push(x+"");//状态msSymble.push(tis.getTop().getCategory());//符号if(tis.getTop().getCategory().equals("id"))msSmtm.push(idt.getId(Integer.parseInt(tis.getTop().getInside())).getName());elsemsSmtm.push("_");tis.pop();}//归约else if(action.charAt(0)=='r'){int y=Integer.parseInt(actNum);output(y);//输出动作说明等if(y==0){//A->id=E;赋值语句的语义子程序，为完成fis.push(new FourItem("=","T"+Ep,"_","%?%"));int i=0;for(;i<cont.getCount();i++)if(cont.getAllConstant()[i].getValue().equals(tt.getTemp(Ep).getValue())){//常数表中已有该常数//id指向该常数idt.getId(Integer.parseInt(tis.getNextTop().getInside())).setValue(i);i=cont.getCount();}if(i==cont.getCount()){//常数表中没有该常数//将常数加入常数表cont.addConstant("int",tt.getTemp(Ep).getValue());//id指向新增常数idt.getId(Integer.parseInt(tis.getNextTop().getInside())).setValue(cont.getCount());}}else if(y==1){E1p=Ep;System.out.println("E1p:"+tt.getTemp(E1p).getValue()+" Tp:"+tt.getTemp(Tp).getValue());//新增临时变量tt.addTemp();Ep=tt.getCount()-1;//加入四元式fis.push(new FourItem("+","T"+E1p,"T"+Tp,"T"+Ep));//执行语义子程序//运算结果的值（常数）String result=Integer.parseInt(tt.getTemp(E1p).getValue())+Integer.parseInt(tt.getTemp(Tp).getValue())+"";tt.getTemp(Ep).setValue(result);}else if(y==2){Ep=Tp;}else if(y==3){T1p=Tp;System.out.println("T1p:"+tt.getTemp(T1p).getValue()+" Fp:"+tt.getTemp(Fp).getValue());//新增临时变量tt.addTemp();Tp=tt.getCount()-1;//加入四元式fis.push(new FourItem("*","T"+T1p,"T"+Fp,"T"+Tp));//执行语义子程序//运算结果的值（常数）String result=""+Integer.parseInt(tt.getTemp(T1p).getValue())*Integer.parseInt(tt.getTemp(Fp).getValue());tt.getTemp(Tp).setValue(result);}else if(y==4){Tp=Fp;}else if(y==5){Fp=Ep;}else if(y==6){//从Id获取常数表的入口，取出常数值，填入临时变量的value中tt.addTemp(cont.getConstant(idt.getId(Integer.parseInt(tis.getNextTop().getInside())).getValue()).getValue());Fp=tt.getCount()-1;}for(int j=0;j<synR[y].length;j++){msStatu.pop();//状态出栈msSymble.pop();//符号出栈msSmtm.pop();//语义出栈}msSymble.push(synL[y]);//符号入栈gt.setTable(msStatu.getTop(), synL[y]);msStatu.push(gt.getGoTo());//状态如栈msSmtm.push("T"+tt.getCount());}}//错误处理public void error(){System.out.println("error，语法错误，输入了多余的符号");//错误处理，简单地认为，多输入了符号tis.pop();}//输出动作public void output(int num){//输出分析过程statu=symble=state=semanteme="";for(int m=0;m<msStatu.getLength();m++)statu+=("|"+msStatu.getAll()[m]);for(int m=0;m<msSymble.getLength();m++)symble+=("|"+msSymble.getAll()[m]);for(int m=0;m<msSmtm.getLength();m++)semanteme+=("|"+msSmtm.getAll()[m]);for(int m=0;m<tis.getLength();m++)state+=("|"+tis.getAll()[m].getCategory());String actionDes=" ";//动作说明if(action.charAt(0)=='r'){//归约actionDes="用"+syntax[num]+"进行规约";}else if(action.equals("acc")){actionDes="分析成功";}else if(action.charAt(0)=='s'){//移进actionDes="状态"+num+"入状态栈";}System.out.println(statu+"\t\t"+symble+"\t\t"+semanteme+"\t\t"+state+"\t\t\t"+action+":"+actionDes);}//getters and setterspublic void setIdt(IdentifierTable idt) {this.idt = idt;}public void setCont(ConstantTable cont) {this.cont = cont;}public void setTt(TemporaryTable tt) {this.tt = tt;}public void setTis(TwoItemStack tis) {this.tis = tis;til=tis.getLength();}public void setFis(FourItemStack fis) {this.fis = fis;}public void outVn(){System.out.println("Ep:"+Ep+" E1p:"+E1p+" Tp:"+Tp+" T1p:"+T1p+" Fp:"+Fp);}}