www.pudn.com > calc5.zip > Scan.h

#if !defined SCAN_H 
#define SCAN_H 
//------------------------------------ 
//  scan.h 
//  (c) Bartosz Milewski, 1994 
//------------------------------------ 
 
#include  
 
enum EToken 
{ 
    tEnd, 
    tError, 
    tNumber, 
    tPlus, 
    tMult, 
    tMinus, 
    tDivide, 
    tLParen, 
    tRParen, 
    tAssign, 
    tIdent 
}; 
 
class Scanner 
{ 
public: 
    Scanner (char const * buf); 
	bool IsDone () const { return _buf [_iLook] == '\0'; } 
	bool IsEmpty () const { return _buf [0] == '\0'; } 
    EToken  Token () { return _token; } 
    EToken  Accept (); 
    int GetSymbolName (char * strOut, int lenBuf); 
    double Number () 
    { 
        assert (_token == tNumber); 
        return _number; 
    } 
private: 
    void EatWhite (); 
 
    char const * const  _buf; 
    int                 _iLook; 
    EToken              _token; 
    double              _number; 
    int                 _iSymbol; 
    int                 _lenSymbol; 
}; 
#endif