Re: Help on record to a Newbie

[Cedric <Cedric.Lannock@gmx.net>]

Am Donnerstag, 27. Dezember 2012 20:31:19 UTC+1 schrieb Cedric:

Hi All,

many thanks for all your help.

I think you got the point: I missed to define the specification and the body of the package.

The things is: I have learnt Pascal sometime and liked it a lot. I have still a book about Pascal containing a set of units that helped me learn programming in Pascal and write my own programs. I thought it would be a good training to use the little knowledge of Ada I have so far and implement the Pascal library in Ada. I think I will come across a lot of difficulties. If I solve them, I will be good in programming Ada in the end.

@Jeffrey:
What is so bad about my programming style? I thought it would be good to have a letter indicating the library I write.

Another question: How do you distinguish between types and variables. When reading my programs I find it a lot easier to see directly if it is a type or a variable. What does your programming style look like?

@Niklas:
Please find below the complete file:

-----------------------------------------------------------
-- file         : t_decl.ads
--
-- date         : 2012-12-20
-- update       : 2012-12-27
--
-- compiler     : GNAT GPL 2012 (20120509)
--
-- Author       : Cedric
-----------------------------------------------------------
-- This file contains general definitions.
-- Types and constants are declared and variables defined.
-----------------------------------------------------------

package t_decl is

  -- types --

  subtype t_str2_type is string (2);
  subtype t_str3_type is string (3);
  subtype t_str4_type is string (4);
  subtype t_str5_type is string (5);
  subtype t_str6_type is string (6);
  subtype t_str7_type is string (7);
  subtype t_str8_type is string (8);
  subtype t_str9_type is string (9);
  subtype t_str10_type is string (10);
  subtype t_str11_type is string (11);
  subtype t_str20_type is string (20);
  subtype t_str30_type is string (30);
  subtype t_str40_type is string (40);
  subtype t_str50_type is string (50);
  subtype t_str60_type is string (60);

  -- maximum length of line
  subtype t_longstring_type is string (127);

  -- work string of 79 characters
  subtype t_workstring_type is string (79);

  type t_yes_type is ('j', 'J');
  type t_no_type is ('n', 'N');

  -- Different alternatives of declaring that type
  -- Alternative 1 is not a good choice
  -- cause the type can get any character instead of
  -- only "J" or "N"
  -- type t_yes_or_no is array(1..1) of character;
  -- Alternative 2 is not a good choice
  -- cause the input of a character can not directly
  -- be compared with that type
  -- type t_yes_or_no is (j, J, n, N);
  -- Alternative 3 is OK
  -- type t_yes_or_no_type is character('j', 'J', 'n', 'N');
  -- Alternative 4 is OK and chosen
  type t_yes_or_no_type is ('j', 'J', 'n', 'N');

  -- This type definition for an array is used to store 500
  -- strings with a maximum length of 10 characters.
  -- This array is handed over to a procedure which converts
  -- the array into numbers of type float. These numbers will
  -- then be processed.
 type t_ary500_str10_type is array (integer range 1 .. 500) of t_str10_type;

  -- The record definition and the type
  -- t_selection_rec_type will be used within the function
  -- t_selection_bar from the unit t_io.
  -- It is assumed that the program will run on terminals
  -- displaying 80 columns and 40 lines.
  subtype t_lines_type   is integer range 1 .. 40;
  subtype t_columns_type is integer range 1 .. 80;
  type t_selection_rec_type is
    record
      label  : string (1 .. 30);
      line   : t_lines_type;
      column : t_columns_type;
    end record;

  type t_bar_type is array (integer range 1 .. 40) of t_selection_rec_type;

  -- For the drop down menu the 8 items of length 20 are
  -- defined.
  type t_ary_menu1_type is array (integer range 1 .. 8) of t_str30_type;

  -- This type definition is used for the selection of the 
  -- terminal and for the setting of foreground and back-
  -- ground colors. The following values can be used:
  type t_terminal_type is (black_n_white, black_n_yellow,
                           black_n_green, color);
  type t_color_type is (red, green, blue, yellow, black, white, grey);
  type t_configure_type is
    record
      terminal   : t_terminal_type;
      foreground,
      background : t_color_type;
    end record;

  -- constants --

  t_esc : constant character := ASCII.ESC;

  -- variables --

  t_key : character; -- for key stroke, e. g. ctrl-key
  t_ok  : boolean;   -- for general use

  -- A type register has to be defined. This type shall be
  -- used to access the processor registers of a standard
  -- Intel processor.
  -- to be done

  -- Error information, e. g. for procedures that convert
  -- something:
  -- t_err := 0 --> Conversion OK
  -- t_err := 1 --> Conversion not OK
  -- The variable will be set to "0" in the unit t_check.
  -- Conversion will be done anyway but with result "0".
  -- Ann.: This way of Turbo Pascal programming has to be
  --       changed to the Ada way of programming.
  t_err : integer range 1 .. 1000;

  -- Terminal type and colors
  t_config : t_configure_type;

  t_yes_no : t_yes_no_type;
  t_yes    : t_yes_type;
  t_no     : t_no_type;

  t_config.terminal   := black_n_white;
  t_config.background := black;
  t_config.foreground := white;

  -- Set the terminal background color
  -- Set the terminal foreground color
  -- to be done, but do not know how to do it
  
  -- Clear the screen
  -- to be done, but do not know how to do it

end t_decl;

-- EOF

Kind regards

Cedric