Re: About a design for a supermarket POS (Point of Sale System)

["Ken Garlington" <Ken.Garlington@computer.org>]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 7434 bytes --]

Well, I ran your code (assuming it was intended to be legal Ada code)
through a tool I have that finds errors in such code. Here's your code with
the errors detected included as comments. (You may want to get a similar
tool for your own use.)

--*****

package POS is

  type Product_Type is -- type definition expected
  subtype Binary_Code is String (1 .. 8) -- missing ";"
  subtype Name is String (1 .. 12) -- missing ";"
  subtype Price is Float range 0.00 .. 1000.00 -- missing ";"
  subtype Quantity is String range 0 .. 1000 -- missing ";"

  type Menu is (Process, Modify, Add, Display1, Display2, Report, Quit)
  -- missing ";"

  type Product is A record -- missing "new"
    Bar-Code : Integer -- missing ","
    Description : Name
    Value : Price
    Restock : Quantity
    Kind : Product_Type
  end record -- no "record" for this "end record"

  Item : Product;

  type Products is array (1, .. 1000) of Product -- missing ".."

  procedure CreateProducts -- missing ";"
  -- Description
  -- Initializes the array The_Products

  procedure NewProduct  -- missing ";"
  -- Description
  -- procedure to allow user to add a new product to the system

  procedure Get ( A_Product : out Product )  -- missing ";"
  -- Description
  -- procedure to prompt user to input full details of a product

end POS;

procedure Point_Of_Sale_System is
   The_Products : Products -- missing ";"
begin
   CreateProducts;
   loop
      DisplayMenu;
      Get(Menu_Choice);
      exit when Menu_Choice = Quit  -- missing ";"
         case Menu_Choice is
         when Process T Process_Shopping_Baskets -- binary operator expected
            when Modify T Modify_Product_Details -- statement expected
            when Add T New_Product -- statement expected
            when Display1 T Display_Products_By_Barcode_Order -- statement
expected
            when Display2 T Display_Products_By_Alphabetic_Name_Order --
statement expected
            when Report T Report_Reorder_Level -- statement expected
            when others T Put("Unexpected Menu Choice!!") -- statement
expected
         end case -- missing ";"
         -- "end loop" expected for "loop" at line 5
      end Point_Of_Sale_System -- missing ";"

--*****

Fixing these problems left the following:

package POS is

  type Product_Type is (Unknown);
  subtype Binary_Code is String (1 .. 8);
  subtype Name is String (1 .. 12);
  subtype Price is Float range 0.00 .. 1000.00;
  subtype Quantity is String range 0 .. 1000; -- invalid "String"

  type Menu is (Process, Modify, Add, Display1, Display2, Report, Quit);

  type Product is record
    Bar-Code : Integer; -- invalid "-"
    Description : Name;
    Value : Price;
    Restock : Quantity;
    Kind : Product_Type;
  end record;

  Item : Product;

  type Products is array (1 .. 1000) of Product;

  procedure CreateProducts;
  -- Description
  -- Initializes the array The_Products

  procedure NewProduct;
  -- Description
  -- procedure to allow user to add a new product to the system

  procedure Get ( A_Product : out Product );
  -- Description
  -- procedure to prompt user to input full details of a product

end POS;

with POS; use POS;
procedure Point_Of_Sale_System is
   The_Products : Products;
begin
   CreateProducts;
   loop
      DisplayMenu; -- undefined
      Get(Menu_Choice); -- Menu_Choice undefined
      exit when Menu_Choice = Quit; -- Menu_Choice undefined
      case Menu_Choice is
         when Process =>
            Process_Shopping_Baskets;  -- undefined
         when Modify =>
            Modify_Product_Details; -- undefined
         when Add =>
            New_Product; -- undefined
         when Display1 =>
            Display_Products_By_Barcode_Order; -- undefined
         when Display2 =>
            Display_Products_By_Alphabetic_Name_Order; -- undefined
         when Report =>
            Report_Reorder_Level; -- undefined
         when others =>
            Put("Unexpected Menu Choice!!"); -- undefined
      end case;
   end loop;
end Point_Of_Sale_System;

"MYC" <fartmanx@hotmail.com> wrote in message
news:97okk9$ll29@tech.port.ac.uk...
: Dear Sir,
:
: I have some problems about Ada.  I am not sure whether it is correct.
Would
: you help me check it?  Thank you very much.
:
: ��The exercise is to write a design for the solution of the problem, which
: simulates aspects of a supermarket POS (Point of Sale System), while the
: design should consist of Ada or pseudo code for the main procedure, a
: definition of all user defined types, a definition of the arrays and / or
: records used and for each subprogram proposed in this solution including
the
: name of the subprogram, an English description of what it does and the
data
: passed into and out of the subprogram.
:
: Also, the user enters an 8 digit binary number (the bar code), which is
: converted to a decimal equivalent.  This decimal value can be used to
locate
: the data for the product.
:
: Moreover, the program is menu driven requiring the following options:
:  Process a shopping basket of goods
:  Modify or add new product details
:  Run off a product inventory by bar code order
:  List product details in alphabetic product name order
:  Report on any product below the (user supplied) re-order level��
:
: Example data and program requirements
:
: BINARY CODE     PRODUCT     PRICE     QUANTITY
: 0000 0001       COFFEE      2.75        27
: 0000 0010       BREAD       0.44       120
: 0000 0011       MILK        0.89        47
: 0000 0100       Nil         0.00         0
:
: 1111 1100       LIME PICKLE 1.59        30
: 1111 1101       Nil         0.00         0
: 1111 1110       BASMATI     3.99        67
: 1111 1111       TOM YUM     0.55        32
:
:
============================================================================
: =
: My solution is as follows:
:
: 1. User Defined Data Types
:
: type PRODUCT_TYPE IS
: subtype BINARY_CODE is STRING (1..8)
: subtype NAME is STRING (1..12)
: subtype PRICE is FLOAT range 0.00..1000.00
: subtype QUANTITY is STRING range 0..1000
:
: type MENU IS (PROCESS, MODIFY, ADD, DISPLAY1, DISPLAY2, REPORT, QUIT)
:
:
: 2. Data Structures �C Records and Arrays
:
: Record to represent a product:
:
: type PRODUCT is a record
: BAR-CODE   : INTEGER
: DESCRIPTION  : NAME
: VALUE    : PRICE
: RESTOCK     : QUANTITY
: KIND     : PRODUCT_TYPE
: end record
: ITEM : PRODUCT;
:
: Array of products:
: type PRODUCTS is array (1,..1000) of PRODUCT
:
: 3. Ada Based Design for Main Procedure
:
: Procedure POINT_OF_SALE_SYSTEM is
: THE_PRODUCTS: PRODUCTS
: begin
: CREATEPRODUCTS;
: loop
: DISPLAYMENU;
: GET(MENU_CHOICE);
: exit when MENU_CHOICE = QUIT
: case MENU_CHOICE is
: when PROCESS T PROCESS_SHOPPING_BASKETS
: when MODIFY  T MODIFY_PRODUCT_DETAILS
: when ADD     T NEW_PRODUCT
: when DISPLAY1 T DISPLAY_PRODUCTS_BY_BARCODE_ORDER
: when DISPLAY2 T DISPLAY_PRODUCTS_BY_ALPHABETIC_NAME_ORDER
: when REPORT T REPORT_REORDER_LEVEL
: when OTHERS T PUT(��Unexpected menu choice!!��)
: end case
: end POINT_OF_SALE_SYSTEM
:
: 4.Subprograms Required
:
: CREATEPRODUCTS
: Description
: Initializes the array THE_PRODUCTS
:
: NEWPRODUCT
: Description
: Procedure to allow user to add a new product to the system
:
: GET(A_PRODUCT: out PRODUCT)
: Description
: Procedure to prompt user to input full details of a product
:
============================================================================
: ===
:
:
:
:
:
: