za.cpp

来自「编译原理课程实验要求做的语法分析」· C++ 代码 · 共 83 行

#include"bianyi.h"


void InitStack(SqStack &Sqstack)
{
	Sqstack.base=(SElemType *)malloc(100*sizeof(SElemType));
	if(!Sqstack.base)
	{
		cout<<"error";
		exit(1);
	}
	Sqstack.top=Sqstack.base;
	Sqstack.stacksize=100;
}

int Rpop(int &Ltrace,int &Lptr,SqStack &Sqstack)
{
	SElemType e;
	if(Sqstack.top==Sqstack.base)
		return 0;
	else
	{
		e=*--Sqstack.top;
		Lptr=e.Lptr;
		Ltrace=e.Ltrace;
		return 1;
	}
}

void Rpush(int Ltrace,int Lptr,SqStack &Sqstack)
{
	SElemType e;
	if(Sqstack.top - Sqstack.base>=Sqstack.stacksize)
	{
		Sqstack.base=(SElemType *)realloc(Sqstack.base,(Sqstack.stacksize+=10)*sizeof(SElemType));
		if(!Sqstack.base)
		{
			cout<<"error";
			exit(1);
		}
			Sqstack.top=Sqstack.base+Sqstack.stacksize;
			Sqstack.stacksize+=10;
	}
	e.Lptr=Lptr;
	e.Ltrace=Ltrace;
	*Sqstack.top++=e;
}

int Rempty(SqStack Sqstack)
{
	if(Sqstack.top==Sqstack.base)
		return 1;
	return 0;
}

void Destroystack(SqStack &Sqstack)
{
	
	while(Sqstack.base)
	{
		Sqstack.top=Sqstack.base+Sqstack.stacksize-1;
		free(Sqstack.top);
		Sqstack.stacksize--;
	}
}
void Rtrail(SqStack &Sqstack,int Fiptr,bool Follow[][36])
{
	SElemType *Mid;
	Mid=(Sqstack.base);
	while(Mid!=Sqstack.top)
	{
		Follow[Mid->Ltrace-128][Fiptr]=1;
		Mid++;
	}
}
void Epop(SqStack &Sqstack)
{
	Sqstack.top=Sqstack.base;
}