//Written by Mo Kashi

//Lexical Analyzer Program

#include<iostream>
#include<fstream>
#include<string>
#include<vector>
ofstream fout,error;
ifstream fin;
int freeze;

class node;
typedef node* nodeptr;
nodeptr box;
//nodeptr top;
vector<nodeptr>tops;
class node{
public:
  void scanner();
  bool isValid(char);
  bool isAlphabet(char);
  bool isDigit(char);
  nodeptr tokenize(nodeptr);
  node();
 // ~node();
  int s;
  int i;
  nodeptr next;
  int address;
  string type;
  string value;
  int line_number;
 };
 node::node(){
 box=NULL;
 }

bool node::isValid(char c){
    if((c>='a'&&c<='z')||(c>='A'&&c<='Z')||(c>='0'&&c<='9')||
        c=='_'||c=='='||c=='<'||c=='>'||c==';'||c=='.'||
        c==','||c=='+'||c=='-'||c=='*'||c=='/'||c==' '||
        c=='('||c==')'||c=='['||c==']'||c=='{'||c=='}'||c==':')
        return true;
    else
        return false;
    }//isValid
bool node::isAlphabet(char c){
    if((c>='a'&&c<='z')||(c>='A'&&c<='Z'))
      return true;
    else
      return false;
  }//isAlphabet
bool node::isDigit(char c){
    if(c>='0'&&c<='9')
      return true;
    else
      return false;
  }//isDigit

nodeptr node::tokenize(nodeptr top){
   return top;
  }//


void node::scanner(){
  fin.open("c:\\input.txt");
   string line;

   line_number=1;
   getline(fin,line);
   while(fin){
     s=line.size();

     i=0;
     string token="";
     string token1;
     while(i!=s){
         if(isAlphabet(line[i])&&isDigit(line[i-1])&&isDigit(token[0])){
            i++;
            cout<<"Number cannot end up with an alphabet in line "<<line_number<<endl;
            error<<"Number cannot end up with an alphabet in line"<<line_number<<endl;
          }//if

       else    if(!isValid(line[i])){
             cout<<line[i]<<"  is not a valid character at line "<<line_number<<endl;
             error<<line[i]<<"  is not a valid character at line "<<line_number<<endl;
             i++;
            }//if


       else if(((line[i]>='a'&&line[i]<='z')||(line[i]>='A'&&line[i]<='Z'))||(((line[i]>='0'&&line[i]<='9')||line[i]=='_')&&token!="")){

              token=token+line[i];

               i++;
               if(!(((line[i]>='a'&&line[i]<='z')||(line[i]>='A'&&line[i]<='Z'))||((line[i]>='0'&&line[i]<='9')||line[i]=='_'))||i==s){
                 box=new node;
                 box->value=token;
                 box->address=line_number;

                 if(token=="and"||token=="not"||token=="or"||
                    token=="in"||token=="out"||token=="fi"||token=="write"||
                    token=="do"||token=="else"||token=="if"||token=="int"||
                    token=="program"||token=="read"||token=="float"||
                    token=="return"||token=="then"||token=="for")

                      box->type="RES";
                 else
                    box->type="ID";

           if(token.size()>15){
             cout<<"Identifier too long in line "<<line_number<<endl;
             error<<"Identifier too long in line "<<line_number<<endl;
           }
           tops.push_back(box);
           token="";
        }//if
     }//if


    else   if(line[i]=='{'||line[i]=='}'||line[i]=='['||
                    line[i]==']'||line[i]=='('||line[i]==')'){
             token=token+line[i];
             i++;
             box=new node;
             box->value=token;
             box->address=line_number;
             box->type="BRA";
             tops.push_back(box);
             token="";
             }//if

          else  if(line[i]==' '){
                  i++;
                }

          else  if(line[i]>='0'&&line[i]<='9'){
                   token=token+line[i];
                   i++;

                   bool first_decimal=true;
                   if(i<s){
                      while((line[i]>='0'&&line[i]<='9')||(line[i]=='.'&&first_decimal)){
                          if(line[i]=='.')
                            first_decimal=false;
                          token=token+line[i];
                          i++;
                          if(i==s)
                            break;
                       }//while
                    }//if
                   box=new node;
                   box->value=token;
                   box->type="NUM";
                   box->address=line_number;
                   tops.push_back(box);
                   if(token.size()>15){
                     cout<<"Numerical overflow occured in line "<<line_number<<endl;
                     error<<"Numerical overflow occured in line "<<line_number<<endl;
                    }

                   token="";
                }//if

          else if(line[i]=='='){
                  token=token+line[i];
                  i++;
                  if(i!=s){
                    if(line[i]=='='){
                      token=token+line[i];
                      i++;
                     }//if
                   }//if
                  box=new node;
                  box->value=token;
                  box->type="OPE";
                  box->address=line_number;
                  tops.push_back(box);
                  token="";
                }//if
          else if(line[i]=='<'){
                token=token+line[i];
                i++;
                if(i!=s){
                  if(line[i]=='>'||line[i]=='='){
                     token=token+line[i];
                     i++;
                   }//if
                 }//if

                box=new node;
                box->value=token;
                box->type="OPE";
                box->address=line_number;
                tops.push_back(box);
                token="";
                }//if

          else if(line[i]=='>'){
                token=token+line[i];
                i++;
                if(i!=s){
                  if(line[i]=='='){
                     token=token+line[i];
                     i++;
                   }//if
                 }//if

                box=new node;
                box->value=token;
                box->type="OPE";
                box->address=line_number;
                tops.push_back(box);
                token="";
                }//if

          else  if(line[i]==';'||line[i]==','||line[i]==':'){
                  token=token+line[i];
                  i++;
                  box=new node;
                  box->value=token;
                  box->type="PUN";
                  box->address=line_number;
                  tops.push_back(box);
                  token="";
                 }//if
          else  if(line[i]=='+'||line[i]=='-'||line[i]=='*'){
                   token=token+line[i];
                   i++;
                   box=new node;
                   box->value=token;
                   box->type="OPE";
                   box->address=line_number;
                   tops.push_back(box);
                   token="";
                 }//if


          else  if(line[i]=='/'){
                   token=token+line[i];
                   i++;
                   if(line[i]!='*'){
                     box=new node;
                     box->value=token;
                     box->type="OPE";
                     box->address=line_number;
                     tops.push_back(box);
                     token="";
                    }//if
                   else{
                      token=token+line[i];
                      i++;
                      box=new node;
                      box->value=token;
                      box->type="COM";
                      box->address=line_number;
                      tops.push_back(box);
                      token="";
                      while(line[i]!='/')
                         i++;
                      token=token+line[i-1]+line[i];
                      i++;
                      box=new node;
                      box->value=token;
                      box->type="COM";
                      box->address=line_number;
                      tops.push_back(box);
                      token="";

                     }//else

                 }//if

      }//while

   getline(fin,line);
   line_number=line_number+1;
   }//while of fin
   }//scanner


// node::~node(){
 //   destroy(top);
 // }



/* void node::destroy(nodeptr& top){
    nodeptr curr,temp;
    curr=top;
    while(curr!=NULL){
       temp=curr;
       curr=curr->next;
       delete temp;
      }//while
  top=NULL;
 }//destroy
  */

void  main(){
 fout.open("c:\\output.txt");
 error.open("c:\\error.txt");
 node obj;
 obj.scanner();
 nodeptr mynode;

 string TYPE="Type of token";
 string VALUE="Value of token";
 string ADDRESS="Address of token(line number)";
 cout<<TYPE;
 fout<<TYPE;
 for(int i=0;i<(20-TYPE.size());i++){
   cout<<" ";
   fout<<" ";
  }//for
  cout<<VALUE;
  fout<<VALUE;
 for(int i=0;i<(20-VALUE.size());i++){
   cout<<" ";
   fout<<" ";
  }//for
 cout<<ADDRESS<<endl;
 fout<<ADDRESS<<endl;
 cout<<"*************"<<"       "<<"**************"<<"      "<<"*****************************"<<endl;
 fout<<"*************"<<"       "<<"**************"<<"      "<<"*****************************"<<endl;

for(int i=0;i<tops.size();i++){
 mynode=obj.tokenize(tops[i]);
 cout<<mynode->type;
 fout<<mynode->type;
  for(int i=0;i<(20-mynode->type.size());i++){
    cout<<" ";
    fout<<" ";
   }//for
  cout<<mynode->value;
  fout<<mynode->value;
  for(int i=0;i<(20-mynode->value.size());i++){
    cout<<" ";
    fout<<" ";
    }//for
  cout<<mynode->address<<endl;
  fout<<mynode->address<<endl;
 }//for
 fout.close();
 cout<<endl<<endl<<endl<<endl;
 cout<<"Enter an integer to exit :  ";
 cin>>freeze;

}//main()