#ifndef __SYMSET_H
#define __SYMSET_H

//lastsym的值指示symbol中共有多少符號(hào)
enum symbol {endfile=-1,nul=0,ident,number,plus,minus,times,
			slash,oddsym,eql,neq,lss,leq,gtr,geq,lparen,
			rparen,comma,semicolon,period,becomes,beginsym,
			endsym,ifsym,thensym,elsesym,whilesym,repeatsym,
			untilsym,writesym,readsym,dosym,callsym,constsym,
			varsym,procsym,lastsym};

class CSymbolSet
{
public:
	CSymbolSet();
	int InSet(symbol sym){return set[sym];}
	CSymbolSet& operator=(const CSymbolSet &ss);
	CSymbolSet& operator+=(const CSymbolSet &ss);
	CSymbolSet& operator+=(const symbol sym){set[sym]=1;return *this;}
private:
	int set[lastsym];
};

inline CSymbolSet::CSymbolSet()
{
	for(int i=0;i<lastsym;i++)
		set[i]=0;
}
inline CSymbolSet& CSymbolSet::operator=(const CSymbolSet &ss)
{
	for (int i=0;i<lastsym;i++)
		set[i]=ss.set[i];
	return *this;
}
inline CSymbolSet& CSymbolSet::operator+=(const CSymbolSet &ss)
{
	for (int i=0;i<lastsym;i++)
		set[i]=set[i]||ss.set[i];
	return *this;
}

#endif //symset.h