(@ 
import java.io.*;
import laforge.persistent.*;
import laforge.lang.*;
import laforge.util.*;   
import java.lang.*;
 @)


LibrarySystem = <users> List(User) <staff> List(Staff) <books> List(Book).

User = "USER" ":" <name> Ident "QUOTA" ":" <quota> Integer 
       [ "BOOKS" "(" <books> List(CheckedOut) ")" ] <nbooks> Integer .

Staff = "STAFF" ":" <name> Ident "PASSWORD" ":" <password> Ident.

Book = <entry> BookEntry "(" <copies>  List(Copy) ")" . 

BookEntry  = "BOOK" ":" "TITLE"   ":" <title>   Ident 
                        "AUTHOR"  ":" <author>  Ident
                        "SUBJECT" ":" <subject> Ident
                        "ISBN"    ":" <isbn>    Ident.   

Copy = <number> Integer ":" <borrower> User <status> Boolean.

CheckedOut = <entry> BookEntry <copy> Copy.





//-------------------------

ListOfCommands = <contents> List(Command).

Command : StaffCommand | UserCommand | GeneralCommand.

UserCommand :  ListBooks     | AuthorSearch | 
               SubjectSearch | UserStatus   .
             
GeneralCommand: UserMode | StaffMode | Logout.

StaffCommand:  CreateAccount | ListUsers    | 
               AddBook       | AddCopy      |
               CheckOut      | Return       |
               ShowStatus    | LastUser     |
               StartC         .



CreateAccount = "CREATE" "ACCOUNT" <person>  Type.

Type : UserType | StaffType.

UserType = "USER" ":" <name> Ident "QUOTA" ":" <quota> Integer.

StaffType = "STAFF" ":" <name> Ident "PASSWORD" ":" <password> Ident. 

ListUsers = "LIST" "USERS".

AddBook = "ADD" <entry> BookEntry "COPIES" ":" <number> Integer .

AddCopy = "ADD" "COPY" "ISBN" ":" <isbn> Ident.

ListBooks = "LIST" "BOOKS" .

AuthorSearch = "FIND" "BOOK" "BY" <author> Ident.

SubjectSearch = "FIND" "BOOK" "ABOUT" <subject> Ident.

CheckOut = "CHECK" "OUT" "ISBN" ":" <isbn> Ident "COPY" "#" <number> Integer
           "FOR" "USER" <name> Ident.

Return = "RETURN" "ISBN" ":" <isbn> Ident "COPY" "#" <number> Integer.

ShowStatus = "SHOW" "STATUS" "OF" <name> Ident.

UserStatus = "STATUS".

LastUser = "LAST" "USER" "BOOK" "ISBN" ":" <isbn> Ident
           "COPY" "#" <number> Integer.

StartC = "START" <file> Ident.

UserMode = "USER" <name> Ident.

StaffMode = "STAFF" <name> Ident "PASSWORD" ":" <password> Ident.

Logout = "LOGOUT".

//--------------------------

List(S) ~ {S}.



Main = .
ActionVisitor = <lsystem> LibrarySystem <mode> Integer <user> Ident 
                  <store> LibrarySystem.
GuardingVisitor = <av> ActionVisitor.
PrintingVisitor =.
SearchingVisitorB = <author> Ident <subject> Ident <books> Book_List.
SearchingVisitorU = <user> User.
SearchingVisitorS = <staff> Staff.
SearchingVisitorISBN = <isbn> Ident <book> Book.
AddingVisitor = <isbn> Ident.