#include<iostream>
#include<string>

using namespace std;
#define openbr "{"
#define closebar "}"


//----------------------------------------------------------------
//----------------------------TOKENTYPE---------------------------
enum TokenType
 {
   	UNKNOWN_TOKEN,
    VARIABLE_IDENTIFIER,
    INTEGER ,
    OPERATOR,
    LEFT_PAREN ,
    RIGHT_PAREN ,
    EOT
 };

 //--------------------------------------------------------------
 //-----------------------TOKEN----------------------------------
 struct Token
 {
 enum TokenType  kind;
 string spelling;
 int lineNo,startingPosition;

 Token(enum TokenType _kind,string _spelling,int _lineNo,int _startingPosition )
   {
        kind=_kind;
	spelling=_spelling;
        lineNo=_lineNo;
        startingPosition=_startingPosition;
   }

 void print()
  {
  cout<<"Token:"<<endl;
  cout<<"TokenType: "<<kind	<<"  Spelling: "<<spelling<<endl;
  cout<<""line number: "<< lineNo<<"  starting postion"<<startingPosition<<endl;
  }
 } ;
 //-------------------------------------------------------------
 //-------------------------------------------------------------
  class LexicalScanner
{

private:

   char CurrentChar;
   string CurrentSpelling;
   enum TokenType CurrentKind;
   istream inputStream;
   int lineno,startingpo;
public:
  
   LexicalScanner(istream _inputstream);
   void skipspaceAndcomment();
   enum TokenType  scanToken();
   Token scan();

private:

void takeit();     
void take(char expectedChar);



};
  LexicalScanner::LexicalScanner(istream _inputstream)
{
  inputStream=(_inputstream);
  CurrentKind=(UNKNOWN_TOKEN);
  CurrentChar=(EOT);
  CurrentSpelling("");
  lineno=startingpo=0;

 inputStream.get(CurrentChar);

  


}
 void LexicalScanner:: skipspaceAndcomment()
 {
	 
	  while(CurrentChar!="" ||CurrentChar!="\n"||CurrentChar!="\t")
	  {
            if(CurrentChar==openbr )
			{
				while(CurrentChar!=closebar)
                        inputStream.get(CurrentChar);

			}
        else
         CurrentSpelling+=CurrentChar;
 }}