guo.c

词法分析器, 词法分析器, 词法分析器, 词法分析器, 词法分析器,

char ch;
main()
{
int code,value;
    char strToken[];
    strToken="";
GetChar();GetBC();
if (IsLetter())
  {	while(IsLtter() or IsDigit())
	{ Concat();GetChar();
	}
	Retract();
	code=Reserve();
	if(code=0)
	  {value=InsertId(strToken);
	   return($ID,value);}
	else
	  return(code,-);
 }
elseif(IsDigit())
       {
	while(Isdigit())
	{Concat();GetChar();}

	Retract();
	value=InsertConst(strToken);
	return($INT,value);
       }
elseif (ch='=') return($ASSIGN,-);
elseif (ch='+') return($PLUS,-);
elseif (ch='*')
     { GetChar()
	if (ch='*')return($POWER,-);
	Retract();return($STAR,-);

     }
 elseif (ch=';') return($STMICOLON,-);
 elseif (ch='(') return($LPAR,-);
 elseif (ch=')') return($RPAR,-);
 elseif (ch='{') return($LBRACE,-);
 elseif (ch='}') return($RBRAE,-);
 else ProcError();

}
GetBC()
{
 if ch=''
  GetChar();
}
Retract()
{ if return() ch='';
}