SjhPVYxv

1//Joseph William Delisle
2//MU7977
3//1/28/2018
4#include <iostream>
5#include <fstream>
6#include <string>
7#include <vector>
8#include <string>
9#include <map>
10#include <regex>
11using namespace std;
12struct symbol//symbol struct holds the type and how many times it has appeared
13{
14    int counter;
15    string symbolType;
16};
17map<string,symbol> symbolTable;//create map as our symbol table
18vector<string>::iterator iter;//iterator to search keywords later
19vector<string> keywords={"if","else","then","while","begin","end"};
20//it takes the token and makes and instantiates a symbol struct to store the number of times it has shown up and what its class is
21void AddToMap(map<string,symbol> &mapa,string inToken,string classType)
22{
23    std::map<string,symbol>::iterator it;//make map iterator to search the map
24        symbol type;//instantiate symbol
25        type.counter=1;
26        type.symbolType = (classType);
27        it = symbolTable.find(inToken); //attempt to find token
28  if (it != symbolTable.end())//if it has been found, increment the counter
29  {
30    it->second.counter++;
31  }
32  else//if not found insert into map
33    {
34        mapa.insert( pair<string,symbol>(inToken,type));
35    }
36}
37
38bool isInVector(vector<string> check, string inToken){
39        iter = find(check.begin(),check.end(),inToken);//try to find inToken in vector
40        if(iter != check.end())//if we didnt fint the token string in the vector return false
41            {
42                return true;
43            }
44            else
45            {
46                return false;
47            }
48    }
49int main()
50{
51    ifstream myfile;
52    string file;
53    while (true) //loop to make sure file exists and can be opened
54    {
55    cout << "Please Enter File Name with extension(file.txt): ";
56    cin >> file;
57    myfile.open(file);
58    if (myfile) break; //break out of while loop if file exists and has been opened
59    cout << "Invalid file. " << endl;
60    }
61
62    string s( (istreambuf_iterator<char>(myfile) ),(istreambuf_iterator<char>()) );//read whole file into a string for manipulation
63    regex specialsFinder (R"([-=,*+/;()\[\]\\])");   //find all the special character
64    regex realFinder(R"([0-9]+(\.[0-9]*)+)");//find only numbers with a decimal and atleast 1 number
65    regex characterFinder(R"([a-zA-Z_]+)");//finds groups of characters that are 1 or more
66    regex integerFinder(R"(\b\d+\b)");
67    regex_iterator<string::iterator> rend;//creating in iterator for our end
68    regex_iterator<string::iterator> sf ( s.begin(), s.end(), specialsFinder);//create iterator for special character finder
69
70    while (sf!=rend)
71        {
72            AddToMap(symbolTable,sf->str(),"special");//place each found token in map
73            ++sf;//increments the iterator
74        }
75
76    regex_iterator<string::iterator> rf ( s.begin(), s.end(), realFinder );//create iterator for reals finder
77
78    while (rf!=rend)
79        {
80            AddToMap(symbolTable,rf->str(),"real");//add real
81            ++rf;//move to next token
82        }
83    s = regex_replace(s,realFinder,"");//gets rid of doubles so regex doesn't re-find the numbers by accident
84
85    regex_iterator<string::iterator> cf ( s.begin(), s.end(), characterFinder );
86    while (cf!=rend)
87        {
88            if(isInVector(keywords, cf->str()))//determine if token is keyword or identifier
89            {
90                AddToMap(symbolTable,cf->str(),"Keyword");//add keyword
91            }
92            else
93            {
94                AddToMap(symbolTable,cf->str(),"Identifier");//add identifier
95            }
96            ++cf;//move to next token
97        }
98
99    regex_iterator<string::iterator> intf ( s.begin(), s.end(), integerFinder);//create iterator for integer finder
100    while (intf!=rend)
101        {
102            AddToMap(symbolTable,intf->str(),"Integer");//add integer
103            ++intf;//move to next token
104        }
105
106    using iterator = map< string, symbol >::iterator;  //print the contents of the map
107    for ( iterator iter = symbolTable.begin(); iter != symbolTable.end(); ++iter )//iterate through whole symbol table and print out everything with its type and count
108    {
109        cout << "The symbol is: " << iter->first<< " and it shows up:   " << iter->second.counter << "  times and is of type: " << iter->second.symbolType << endl << endl;//print out everything
110    }
111
112  return 0;
113}