Simple Interpreter

java_Interpreter_code.txt

Let x = 1
Let y = 3
Let z = 0
z = x + y
print[z] 

java_Interpreter_Interpret.java

package Interpreter;

/**
 * Created by Sanitarium on 4/29/2016.
 */

import javafx.util.Pair;

import java.io.*;
import java.*;
import java.util.*;

public class Interpret {
    public static void read()
    {
        try
        {
            File file = new File("C:\\Users\\Sanitarium\\IdeaProjects\\Interpreter\\src\\java\\Interpreter\\code.txt");
            FileReader fileReader = new FileReader(file);
            BufferedReader bufferedReader = new BufferedReader(fileReader);
            StringBuffer stringBuffer =  new StringBuffer();
            String line = null;
            boolean var = false;
            boolean operation = false;
            //public static int x = 0; public static int y = 0; public static int z = 0;//variables
            //List<Integer> values = new ArrayList<Integer>();
            HashMap<String, Integer> ValuesMap = new HashMap<String,Integer>();


            while ((line = bufferedReader.readLine()) != null)
            {
                System.out.println(line);
                //do this for each line........
                String[] tokens = line.split(" ");
                System.out.println(tokens.length);

                int  i = 0;
                    System.out.println(tokens[i]);

                if(tokens[i].contentEquals("Let") &&  tokens[i+2].contentEquals("="))// upcoming variable
                    {
                        ValuesMap.put( tokens[i+1], Integer.parseInt( tokens[tokens.length-1] ) );

                    }


                else if( ValuesMap.containsKey(tokens[i]) && tokens[i+1].contentEquals("=") )
                    {
                        int temp =0;
                        int lValue = ValuesMap.get(tokens[i+2]);
                        int RValue = ValuesMap.get(tokens[i+4]);
                        if (tokens[i+3].contentEquals("+"))
                        {
                           temp = lValue + RValue;
                        }
                        else if (tokens[i+3].contentEquals("-"))
                        {
                            temp = lValue - RValue;
                        }

                        ValuesMap.put(tokens[i], temp);
                    }

                else if (tokens[i].contains("print"))
                {
                    System.out.println(ValuesMap.get("z"));
                }



            }

            fileReader.close();
            System.out.println("-----------\n\nEOF!\n");
            System.out.println(ValuesMap);
//            System.out.println("list size"+values.size());
//            for(int i=0; i<values.size(); i++)
//            {
//                System.out.println(values.get(i));
//            }
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }



    public static void main(String[] args)
    {
        read();
    }

}