(****
 *
 * Module Search is the window that comes up when some starts a new 
 * search or redefines a search.
 *
 *)
--module Search;
--from Bank import QuestionBank;
--from ManageQuestion import ClassName, Type, Difficulty, Time, QuestionText, Answer;


  operation FilterByClass is
    inputs: qb:QuestionBank, c:ClassName*;
    outputs: qb':QuestionBank;
    description: 
	(*
         * Filters a question bank for the selected classes
    	 *);
    precondition: ;
    postcondition:
        (*
         * All questions that were in the question bank before and match any 
	 * of the Classes are still in the bank otherwise they aren't.
         *);
  end FilterByClass;

  operation FilterByType is
    inputs: qb:QuestionBank, t:Type*;
    outputs: qb':QuestionBank;
    description: 
	(*
         * Filters a question bank for the selected Types
    	 *);
    precondition: ;
    postcondition:
        (*
         * All questions that were in the question bank before and match any
         * of the Types are still in the bank otherwise they aren't.
         *);
  end FilterByType;

  operation FilterByDifficulty is
    inputs: qb:QuestionBank, sd:StartDifficulty, ed:EndDifficulty;
    outputs: qb':QuestionBank;
    description: 
	(*
         * Filters a question bank for questions between the difficulties
    	 *);
    precondition: ;
    postcondition:
        (*
         * All questions that were in the question bank before and are within
         * start and end difficulty inclusive are still in the bank otherwise
	 * they aren't.
         *);
  end FilterByDifficulty;

  object StartDifficulty is Difficulty;
  object EndDifficulty is Difficulty;

  operation FilterByTime is
    inputs: qb:QuestionBank, st:StartTime, et:EndTime;
    outputs: qb':QuestionBank;
    description: 
	(*
         * Filters a question bank for questions between the times
    	 *);
    precondition: ;
    postcondition:
        (*
         * All questions that were in the question bank before and are within
         * start and end time inclusive are still in the bank otherwise they 
	 * aren't.
         *);
  end FilterByTime;

  object StartTime is Time;
  object EndTime is Time;

  operation SearchForKeyword is
    inputs: qb:QuestionBank, k:Keyword*;
    outputs: qb':QuestionBank;
    description: 
	(*
         * Searches a question bank for question, answer or topic fields that 
	 * match the given keywords
    	 *);
    precondition: ;
    postcondition:
        (*
         * All questions that were in the question bank before and match all 
	 * of the keywords in their QuestionText, Answer, or Topic are still 
	 * in the bank otherwise they aren't.
         *);
  end SearchForKeyword;

  object Keyword is string;

--end Search;