symbol.cpp

来自「编译原理实验将简单中缀算术表达式变换成后缀形式」· C++ 代码 · 共 36 行

//symbol.c
#include "stdafx.h"
#include "global.h"

#define STRMAX 999
#define SYMMAX 100

char lexemes[STRMAX];
int lastchar=-1;
struct entry symtable[SYMMAX];
int lastentry=0;

int lookup(char s[])
{
	int p;
	for(p=lastentry;p>0;p=p-1)
		if(strcmp(symtable[p].lexptr,s)==0)
			return p;
		return 0;
}

int insert(char s[],int tok)
{
	int len;
	len=strlen(s);
	if(lastentry+1>=SYMMAX)
		error("symbol table full");
	if(lastchar+len+1>=STRMAX)
		error("lexemes array full");
	lastentry=lastentry+1;
	symtable[lastentry].token=tok;
	symtable[lastentry].lexptr=&lexemes[lastchar+1];
	lastchar=lastchar+len+1;
	strcpy(symtable[lastentry].lexptr,s);
	return lastentry;
}