1 /*
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  4  * and open the template in the editor.
  5  */
  6 package arrayplay;
  7 
  8 import java.io.File;
  9 import java.io.FileNotFoundException;
 10 import java.util.Scanner;
 11 
 12 /**
 13  *
 14  * @author ssingh6
 15  */
 16 public class WordList{
 17 
 18     /**
 19      * @param args the command line arguments
 20      */
 21   private static final int LIMIT = 1000;
 22      private static String[] words = new String[LIMIT];
 23       private static int numberOfWords = 0;
 24      private static Scanner commandReader = new Scanner(System.in);
 25  
 26   
 27     public static void main(String[] args) {
 28          try {
 29               //ESTABLIS ARRAY OF WORDS
 30               readWords();
 31               // CHECK THE DATA
 32               //System.out.println("\nThe original list of words ...");
 33               //displayWords();
 34               //ENTER THE INTERPRETER
 35               interpreter();
 36           } catch (FileNotFoundException ex) {
 37               System.out.println("The file was not found. Please think again.");
 38               System.exit(-1);
 39           }
 40       }
 41   
 42       // Assuming that the data file will be found in the public_html/data
 43       // subdirectory of the user's home directory
 44       private static Scanner establishScanner(String fn) throws FileNotFoundException {
 45           String separator = System.getProperty("file.separator");
 46           String homeDirectory = System.getProperty("user.home");
 47           String path = homeDirectory + separator + "CS1Files" + separator + "data" + separator;
 48          String fullFileName = path + fn;
 49           return new Scanner(new File(fullFileName));
 50       }
 51       private static void readWords() throws FileNotFoundException {
 52           Scanner scanner = establishScanner("WordSet.txt");
 53           while (scanner.hasNext()) {
 54               words[numberOfWords] = scanner.next();
 55               numberOfWords ++;
 56           }
 57       }
 58   
 59       private static void displayWords() {
 60           for (int x = 0; x < numberOfWords; x ++) {
 61               System.out.println(words[x]);
 62           }
 63       }
 64   
 65       private static void interpreter() {
 66          System.out.print(">>>");
 67          String command = commandReader.next();
 68           if (command.equalsIgnoreCase("DISPLAY")) {
 69              interpreterDisplayCommand();
 70           } else if (command.equalsIgnoreCase("PRINT")) {
 71              interpreterPrintCommand();
 72           } else if (command.equalsIgnoreCase("SWAP")) {
 73               interpreterSwapCommand();
 74           } else if (command.equalsIgnoreCase("ADD")) {
 75               interpreterAddCommand();
 76           } else if (command.equalsIgnoreCase("HELP")) {
 77               interpreterHelpCommand();
 78           } else if (command.equalsIgnoreCase("EXIT")) {
 79               System.exit(0);
 80          } else {
 81               System.out.println("### Unrecognizable command: " + command);
 82           } 
 83           System.out.print("\n");
 84           interpreter();
 85      }
 86   
 87       private static void interpreterDisplayCommand() {
 88           displayWords();
 89       }
 90   
 91       private static void interpreterPrintCommand() {
 92           String operand = commandReader.next();
 93           if (operand.equalsIgnoreCase("FIRST")) {
 94               System.out.println(words[0]);
 95           } else if (operand.equalsIgnoreCase("LAST")) {
 96               System.out.println(words[numberOfWords-1]);
 97           } else {
 98              int index = Integer.valueOf(operand);
 99              System.out.println(words[index-1]);
100          }
101      }
102  
103      private static void interpreterSwapCommand() {
104          int position1 = commandReader.nextInt();
105          int position2 = commandReader.nextInt();
106          String temp = words[position1 - 1];
107          words[position1 - 1] = words[position2 - 1];
108          words[position2 - 1] = temp;
109      }
110  
111      private static void interpreterAddCommand() {
112          String position = commandReader.next();
113          if (position.equalsIgnoreCase("LAST")) {
114              addLast();
115          } else if (position.equalsIgnoreCase("FIRST")) {
116              addFirst();
117          } else {
118             System.out.println("### Invalid operand for add command");
119          }
120          numberOfWords ++;
121      }
122  
123      private static void interpreterHelpCommand() {
124          System.out.println("HELP    - display menu of commands");
125          System.out.println("DISPLAY - display the list of words");
126          System.out.println("PRINT   - print a word (FIRST; LAST; nth)");
127         System.out.println("SWAP    - exchange two elements (nth; mth)");
128          System.out.println("ADD     - add a word to the list (FIRST; LAST)");
129          System.out.println("EXIT    - terminate execution of the program");
130      }
131  
132      private static void addFirst() {
133         for (int x = numberOfWords; x > 0; x --) {
134              words[x] = words[x - 1];
135          }
136          words[0] = commandReader.next();
137      }
138  
139      private static void addLast() {
140          words[numberOfWords] = commandReader.next();
141     }
142      
143 }
144  
145