/* FILE NAME: LabOps.java
 * AUTHOR: Stella K.
 *
 * DATE: Oct 26, 07
 *
 * COMMENTS: Solutions to lab methods on StringLists.
 * Notice that this class extends StringListOps, which extends StringList.
 * Therefore, all methods defined in these two classes are inhereted here.
 * 
 * In particular:
 * The following methods are inherited from StringList:
 * public static StringList empty();
 * public static boolean isEmpty (StringList L);
 * public static StringList prepend (String s, StringList L);
 * public static String head (StringList L);
 * public static StringList tail (StringList L);
 * public static boolean equals (StringList L1, StringList L2);
 * public static String toString (StringList L);
 * public static String fromString (String s);
 * 
 * The following methods are inherited from StringList:
 * public static int length (StringList L);
 * public static StringList append (StringList L1, StringList L2);
 * public static StringList postpend (StringList L, String s);
 * public static StringList reverse (StringList L);
 * 
 * All the above methods can be used in this file without the explicit 
 * "StringList." or "StringListOps." prefixes.
 * For example, you can write "head(L)" rather than "StringList.head(L)",
 * and "length(L)" rather than "StringListOps.length(L)".
 * 
 * MODIFICATION HISTORY:
*/    

public class LabOpsSolutionsStella extends StringListOps {
 // Write your methods here:
 
 
  
   public static void main (String [] args) {
 
     //testing the f=given auxiliary methods
  System.out.println("first(\"cs111\") = \"" + first("cs111") + "\"");
  System.out.println("butFirst(\"cs111\") = \"" + butFirst("cs111") + "\"");
  System.out.println("fromString(\"[I,do,not,like,green,eggs,and,ham]\") = "
                      + fromString("[I,do,not,like,green,eggs,and,ham]"));  
    // Add your testing code here:
  
     
     
  //Lists for testing
  StringList  testList0 = empty();
  StringList  testList1 = prepend("person", empty());
  StringList  testList2 = prepend("cat", prepend("desk", empty()));
  StringList  testList3 = prepend("hello", prepend("low", prepend("sun", empty())));
  StringList  testList8 = fromString(("[I,do,not,like,green,eggs,and,ham]"));
                   
     
  //Testing mapPluralize()
  System.out.println("Testing mapPluralize()");
  StringList result2 = mapPluralize(testList2);
  System.out.println(testList0.toString() + " mapPularize --> " + mapPluralize(testList0));
  System.out.println(testList1.toString() + " mapPularize --> " + mapPluralize(testList1));
  System.out.println(testList2.toString() + " mapPularize --> " + result2);
  System.out.println(testList3.toString() + " mapPularize --> " + mapPluralize(testList3));
  
    //Testing mapUpperCase()
  System.out.println("\nTesting mapUpperCase()");
  System.out.println(testList0.toString() + " mapUpperCase --> " + mapUpperCase(testList0));
  System.out.println(testList1.toString() + " mapUpperCase --> " + mapUpperCase(testList1));
  System.out.println(testList2.toString() + " mapUpperCase --> " + mapUpperCase(testList2));
  System.out.println(testList3.toString() + " mapUpperCase --> " + mapUpperCase(testList3));
  
  //Testing isMember()
  System.out.println("\nTesting isMember()");
  System.out.println("stella is member in " + testList0.toString() + " --> " + isMember("stella", testList0));
  System.out.println("stella is member in " + testList1.toString() + " --> " + isMember("stella", testList1));
  System.out.println("person is member in " + testList2.toString() + " --> " + isMember("person", testList2));
  System.out.println("desk is member in " + testList2.toString() + " --> " + isMember("desk", testList2));
  
  
  //Testing explode()
  System.out.println("\nTesting explode()");
  System.out.println("stella" + " explode --> " + explode("stella"));
  System.out.println("desk explode --> " + explode("desk"));
  System.out.println("spaceship explode --> " + explode("spaceship"));
  System.out.println("empty string explode --> " + explode(""));

  //Testing implode()
  System.out.println("\nTesting implode()");
  System.out.println("implode" + testList0.toString() + " --> " + implode(testList0));
  System.out.println("implode " + testList1.toString() + " --> " + implode(testList1));
  System.out.println("implode " + testList2.toString() + " --> " + implode(testList2));
  System.out.println("implode " + testList3.toString() + " --> " + implode(testList3));
  System.out.println("implode(" + testList8.toString() + " --> " + implode(testList8));
      
     
    // Testing filterMatches()
     System.out.println("\nTesting filterMatches()");
    StringList result = filterMatches("com", fromString("[computer,program,incomparable,intercom,Java]"));
    System.out.println("filterMatches(com, [computer,program,incomparable,intercom,Java] --> " +
                        result);
   
    result = filterMatches("com", fromString("[cat,dog,mouse]"));
    System.out.println("filterMatches(com, [cat,dog,mouse] --> " + result);
  
     // Testing insert()
     System.out.println("\nTesting insert()");
     System.out.println(insert("e", fromString("[b,d,f]")));
  
   }
   
   
 
 public static StringList mapPluralize (StringList l) {
   if (isEmpty(l)) return empty();
   String s = head(l) + "s";
   return prepend(s, mapPluralize(tail(l)));
 }
 
  public static StringList mapUpperCase (StringList l) {
   if (isEmpty(l)) return empty();
   String s = head(l).toUpperCase();
   return prepend(s, mapUpperCase(tail(l)));
 } 
  
   public static boolean isMember(String s, StringList l) {
     if (isEmpty(l)) return false;
     if (s.equals(head(l))) return true;
     return isMember(s, tail(l));
 } 
   //It takes a string as an argument and returns a list of single-character strings
   //formed out of the characters of the given string s.
   //for example: "hello" -->["h","e","l","l","o"]
   public static StringList explode (String s) {
     if (s.equals("")) return empty();
     String str = first(s);
     return prepend(str, explode(butFirst(s)));
   }
   
   //It takes a string list and returns a string that is the result of concatenating
   //all the strings in the input list in order.
   public static String implode (StringList l) {
     if (isEmpty(l)) return "";
     return head(l)+implode(tail(l));
   }
    
   
   //Checks whether the String sub is a sub-string of the String str
   public static boolean isSubstring(String sub, String str) {
     int res = str.indexOf(sub);  //find the index of the sub into str
     if (res < 0) return false; // if it was found there, return true, false otherwise.
     return true;
   }
   
   
   //It takes a string and a string list, and returns 
   //the list of strings in the input list that contain the input string as a substring.
   public static StringList filterMatches(String str, StringList L) {
     if (isEmpty(L)) return empty();  //base case
     //System.out.println("str = " + str);
     //System.out.println("head(L) = " + head(L));
     //System.out.println(isSubstring(str, head(L)));
     StringList res = filterMatches(str, tail(L));
     if (isSubstring(str, head(L))) 
       return prepend(head(L), res);
     else return res;
   }
     //Returns a new (n+1)-element list 
   //of alphabetically sorted strings that contains the input string
   //in addition to all the elements of L.
   public static StringList insert (String s, StringList L) {
     if (isEmpty(L)) return prepend(s, empty());
     
     if (s.compareTo(head(L)) <= 0)
       return prepend(s, L);
     else { // insert s in the right place within the tail of L
       return prepend(head(L), insert(s, tail(L)));
     }
   }
  
 //---------------------------------------------------------------
 // The following auxiliary methods are helpful for defining explode()
 
 // Given a string s, returns a one-character string containing
 // the first character of s. 
 public static String first (String s) {
  return new Character(s.charAt(0)).toString();
 }

 
 // Given a string s, returns the substring of s that contains
 // all characters except the first. 
 public static String butFirst (String s) {
  return s.substring(1,s.length());
 }

 
}