// Lab 5
// CS U213 Fall 2008
// strings-acc.java

import java.util.*;

// to represent a list of Strings
interface ILoS{
  // combine all Strings in this list into one
  String combine();
  
  // find the length of the longest word in this list
  int maxLength();
}

// to represent an empty list of Strings
class MtLoS implements ILoS{
  MtLoS(){}
  
  // combine all Strings in this list into one
  String combine(){
    return "";
  }  

  // find the length of the longest word in this list
  int maxLength(){
    return 0;
  }
}

// to represent a nonempty list of Strings
class ConsLoS implements ILoS{
  String first;
  ILoS rest;
  
  ConsLoS(String first, ILoS rest){
    this.first = first;
    this.rest = rest;  
  }
  
  // combine all Strings in this list into one
  String combine(){
    return this.first.concat(this.rest.combine());
  }  

  // find the length of the longest word in this list
  int maxLength(){
    return Math.max(this.first.length(), this.rest.maxLength());
  }
}

// to represent examples for lists of strings
class Examples{
  Examples(){}
  
  ILoS mary = new ConsLoS("Mary ",
               new ConsLoS("had ",
                new ConsLoS("a ",
                 new ConsLoS("little ",
                  new ConsLoS("lamb.", new MtLoS())))));
   
  // test for the method combine for the list of Strings                       
  boolean testCombine = check this.mary.combine() 
                        expect "Mary had a little lamb.";

  // test for the method maxLength for the list of Strings                       
  boolean testMaxLength = check this.mary.maxLength() expect 7;
  
}