编译原理虎书java版本Chapter 1

Count.java

public class  Count
{
 int resolveStm(Stm stm){
  int temp1=0,temp2=0;
  if(stm.kind==1){
   temp1=resolveStm(((CompoundStm)stm).stm1);
   temp2=resolveStm(((CompoundStm)stm).stm2);
   return temp1>temp2? temp1:temp2;
  }else if(stm.kind==2){
   return resolveExp(((AssignStm)stm).exp);
  }else if (stm.kind==3){
   return countExpInExpList(((PrintStm)stm).exps);
  }else{
   return 0;
  }
 }

 int countExpInExpList(ExpList expList){
  if(expList.kind==1){
   return 1;
  }else if(expList.kind==2){
   return 1+countExpInExpList(((PairExpList)expList).tail);
  }else{
   return 0;
  }
 }

 int resolveExp(Exp exp){
  int temp1,temp2;  
  if(exp.kind==1){  
   return 0;  
   }else if(exp.kind==2){
    return 0;  
   }else if(exp.kind==3){  
    temp1 = resolveExp(((OpExp)exp).left);  
    temp2 = resolveExp(((OpExp)exp).right);  
    return temp1>temp2?temp1:temp2; 
   }else if(exp.kind==4){
    temp1=resolveStm(((EseqExp)exp).stm);
    temp2=resolveExp(((EseqExp)exp).exp);
    return temp1>temp2?temp1:temp2;
   }else{
    return 0;
    }  
   }

 int resolveExpList(ExpList expList){
  int temp1,temp2; 
  if(expList.kind==2){  
   temp1 = resolveExp(((PairExpList)expList).head);  
   temp2 = resolveExpList(((PairExpList)expList).tail);  
   return temp1>temp2?temp1:temp2;
   }else if(expList.kind==1){  
    return resolveExp(((LastExpList)expList).last);
   }else{  
     return 0;
   }
 }
}

Interp.java

public class  Interp
{
 void startinterpStm(Stm stm){
  Table t=new Table(null,0,null);
  interpStm(stm,t);
 }

 Table interpStm(Stm stm,Table t){
  if(stm.kind==1){
   Table t1=interpStm(((CompoundStm)stm).stm1,t);
   Table t2=interpStm(((CompoundStm)stm).stm2,t1);
   return t2;
  }else if(stm.kind==2){
   IntAndTable it1 = interExp(((AssignStm)stm).exp,t);
   Table t1=update(it1.t,((AssignStm)stm).id,it1.i);
   return t1;
  }else if(stm.kind==3){
   printExplist(((PrintStm)stm).exps,t);
   return t;
  }else{
   return t;
   }
 }
 
 IntAndTable interExp(Exp exp,Table t){
  if(exp.kind==1){
   int temp=lookup(t,((IdExp)exp).id);
   return new IntAndTable(temp,t);
  }else if(exp.kind==2){
   return new IntAndTable(((NumExp)exp).num,t);
  }else if(exp.kind==3){
   IntAndTable it1= interExp(((OpExp)exp).left,t);
   IntAndTable it2= interExp(((OpExp)exp).right,it1.t);
   int x1,x2,result;
   x1=it1.i;
   x2=it2.i;
   if(((OpExp)exp).oper==1){
    result=x1+x2;
   }else if(((OpExp)exp).oper==2){
    result=x1-x2;
   }else if(((OpExp)exp).oper==3){
    result=x1*x2;
   }else if(((OpExp)exp).oper==4){
    result=x1/x2;
   }else{
    result=0;
   }
   return new IntAndTable(result,t);
  }else if(exp.kind==4){
   Table t1=interpStm(((EseqExp)exp).stm,t);
   IntAndTable t3= interExp(((EseqExp)exp).exp,t1);
   return t3;
  }else{
   return new IntAndTable(0,t);
  }
 }
 
    Table update(Table t1,String i,int v){
  Table t2=new Table(i,v,t1);
  return t2;
 }

 int lookup(Table t,String key){
  if(key.compareTo(t.id)==0){
   return t.value;
  }else return lookup(t.tail,key);
 }

 void printExplist(ExpList exps,Table t){
  if(exps.kind==1){
   IntAndTable temp=interExp(((LastExpList)exps).last,t);
   System.out.println(temp.i);
  }else if(exps.kind==2){
   IntAndTable temp=interExp(((PairExpList)exps).head,t);
   System.out.print(temp.i+" ");
   printExplist(((PairExpList)exps).tail,t);
  }else return;
 }

// IntAndTable interExpList(ExpList explist,Table t){

// }
}

class Table
{
 String id;
 int value;
 Table tail;
 Table(String i,int v,Table t){id=i;value=v;tail=t;}
}

class IntAndTable
{
 int i;
 Table t;
 IntAndTable(int ii,Table tt){i=ii;t=tt;};
}