symbol.h

这个是编译原理的词法分析的实验报告！很不错

#ifndef SYMBOL_H
#define SYMBOL_H



#include "global.h"
#include "error.h"


int lastchar=-1;			//one-dimentional array index
int lastentry=0;			//current entry index


int insert(char *s, int tok);		
int lookup(char *s);



int lookup(char *s)							//look up index according to lexeme
{
	int p;
	for(p=lastentry;p>0;p--)
	{
		if(strcmp(symtable[p].lexptr,s)==0)
			return p;
	}
		return 0;

}


int insert(char *s, int tok)			//insert a new record in symbol table
{
	int len;
	len=strlen(s);
	if(lastentry+1>=SYMMAX)
		error("symbol table full");
	if(lastchar+len+1>=STRMAX)
		error("lexeme array full");
	lastentry++;

	//assignment
	symtable[lastentry].token=tok;
	symtable[lastentry].lexptr=&lexemes[lastchar+1];

	lastchar+=len+1;
	strcpy(symtable[lastentry].lexptr,s);

	return lastentry;		//return the index
}


#endif