resever.h

大学期间写的一个简单的词法分析器,通过输入符合自定义语法规则的程序,得到分析的二元组

#include"iostream.h"
#include"stdlib.h"
class res
{
public:
	char name[11];
	int value;
};
res p0[23]={{"if",1},{"then",2},{"else",3},{"end",4},{"until",5},
{"repeat",6},{"read",7},{"write",8},{"+",9},{"-",9},{"*",9},{"/",9},
{":=",10},{">",11},{"<",11},{">=",11},{"<=",11},{"{",12},{"}",12},
{";",13},{",",14},{"number",15},{"identifier",16}};
int s0[8];
void getvalue()
{   
	int s;
	for(int i=0;i<8;i++){
		s0[i]=0;
		for(int j=0;j<10;j++){
			s=p0[i].name[j];			
			if(s) s0[i]+=s;			
			else break;
		}
	}
}
int match(int m){	
 int k=0;
 for(int i=0;i<23;i++){	 
	 if(m==s0[i]){
		 k=i+1;	     
		 break;
	 }
 }
  return k;
}
int error(int k,char *p)
{
	char id;
			cout<<*p<<"为无法识别的符号,是否继续编译?(y/n)"<<endl;
			cin>>id;
			if(id=='y'){k=1;return k;}
			else {
				cout<<"将结束编译..."<<endl;
		    	exit(1);
			}
}
bool identifier(char *p)
{
	if((*p>='a'&&*p<='z')||(*p>='A'&&*p<='Z'))
		return true;
	else return false;
}
bool number(char *p)
{
	if(*p>='0'&&*p<='9')
		return true;
	else return false;
}