grammer.h

C语言的语法分析器

#ifndef GRAMMER_H
#define GRAMMER_H
#include "iostream.h"
#include "scanner.h"
void lrparser();
void yucu();
void statement();
void factor();
void expression();
void term();
void factor();
int kk=0;
void lrparser()
{
	if(syn==1)
	{
		scanner();
		yucu();
		{
			if(syn==6)
			{
				scanner();
				if(syn==0 && (kk==0))
					cout<<"\nsuccess!"<<endl;
			}
		
			else 
				{
					if(kk!=1)
					{
						cout<<"End is not found!"<<endl;
						kk=1;
					}
					
				}
		}
	}
	else
		{
			cout<<"Begin Error!"<<endl;
			kk=1;
		}	
}
void yucu()
{
	statement();
	while(syn==26)
	{
		scanner();
		statement();
	}
}

void statement()
{
	if(syn==10)
	{
		scanner();
		if(syn==18)
		{
			scanner();
			expression();
		}
		else
		{
			cout<<"= error!"<<endl;
			kk=1;
		}
	}
	else
		{
			cout<<"yuju error!"<<endl;
			kk=1;
		}
}

void expression()
{
	term();
	while(syn==13||syn==14)
	{
		scanner();
		term();
	}
}
void term()
{
	factor();
	if(syn==15||syn==16)
	{
		scanner();
		factor();
	}
}
void factor()
{
	if(syn==10||syn==11)
		scanner();
	else if(syn==27)
	{
		scanner();
		expression();
		if(syn==28)
		scanner();
		else 
		{
			cout<<") Error!"<<endl;
			kk=1;
		}
	}
	else
	{
		cout<<"Expression Error!"<<endl;
		kk=1;
	}
}


#endif GRAMMER_H