Re: Help with an errant 'IF' statement please.

[Austin Obyrne <austin.obyrne@hotmail.com>]

On Monday, December 1, 2014 10:20:52 PM UTC, Stephen Leake wrote:
> Austin Obyrne <austin.obyrne@hotmail.com> writes:
> 
> >>   Time_Ex_1;
> >>   Count  := Phi;    --initialising change-of-origin Count
> 
> <snip>
> 
> In order to help you understand what you need to change in this post so
> we can help, I've attempted to make this compile. Here's a modified
> version, with some fixes, and some FIXME: comments:
> 
> with Ada.Text_IO;
> procedure Obyrne_1
> is
>    --  FIXME: put all required definitions here, as reported by the
>    --  compilation errors: Time_Ex_1, Count, Phi, Resets, Total, n,
>    --  Number, NextChar, Line_Number, Sentinel, Span, Counter, Image,
>    --  Compose_CipherText_Items, Q, I_Num, Time_Ex_2
>    --
>    --  While you are doing that, delete any that are not needed to
>    --  show the problem.
> begin
> 
>    Time_Ex_1;
>    Count  := Phi;    --initialising change-of-origin Count
>    Resets := 0;
>    Total  := 0;
>    NextChar := ' ';    --initialising to pre-empt error message
>    Line_Number:= 0;
>    LOOP
>       EXIT WHEN NextChar = Sentinel;
>       Count:= Count+1;               -- change-of-origin count reinitialising
>       IF Count REM (Span + Phi +1) = 0 THEN -- Reset signal
>          Count:= 1;
>          Resets:= Resets +1;
>       END IF;
>       Total := Total +1;
>       Ada.Text_IO.Get(Item => NextChar);
>       Counter := Counter +1;
>       Total := Total +1;
>       Image(Counter):= NextChar;
>       --  FIXME: do _not_ include commented out code, unless it is part of the explanation of the problem
> 
>       --  FIXME: most of this output is _not_ essential to show the bug; delete them.
>       Ada.Text_IO.New_Line;
>       Ada.Text_IO.Put(Item => "         ");
>       Ada.Text_IO.Put(Item => NextChar);
>       Ada.Text_IO.Put(Item => "                - Current PlainText for encryption");
>       Ada.Text_IO.New_Line;
>       Ada.Text_IO.Put(Item => "        ");
>       Ada.Text_IO.Put(Item => " Phi ");
>       Ada.Text_IO.Put(Item => "             - ");
>       Ada.Integer_Text_IO.Put(Item => Phi, Width => 2);
>       Ada.Text_IO.New_Line;
>       Ada.Text_IO.Put(Item => "        ");
>       Ada.Text_IO.Put(Item => " Count ");
>       Ada.Text_IO.Put(Item => "           - ");
>       Ada.Integer_Text_IO.Put(Item => Count, Width => 2);
>       Ada.Text_IO.New_Line;
>       Ada.Text_IO.Put(Item => "        ");
>       Ada.Text_IO.Put(Item => " Total ");
>       Ada.Text_IO.Put(Item => "           - ");
>       Ada.Integer_Text_IO.Put(Item => Total, Width => 2);
>       Ada.Text_IO.New_line;
>       Ada.Integer_Text_IO.Put(Item => Character'Pos(Nextchar), Width => 11);
>       Ada.Text_IO.Put
>         (Item => "               - Value in ASCII of current plaintext");
>       Ada.Text_IO.New_line;
>       Compute_Normal;
>       Ada.Integer_Text_IO.Put(Item => Normal(1), Width => 4);
>       Ada.Integer_Text_IO.Put(Item => Normal(2), Width => 8);
>       Ada.Integer_Text_IO.Put(Item => Normal(3), Width => 8);
>       Ada.Text_IO.Put(Item => "      - Normal vector -  fixed in this cipher");
>       Ada.Text_IO.New_Line;
>       Ada.Integer_Text_IO.Put(Item => S_1, Width => 4);
>       Ada.Integer_Text_IO.Put(Item => S_2, Width => 8);
>       Ada.Integer_Text_IO.Put(Item => S_3, Width => 8);
>       Ada.Text_IO.Put
>         (Item => "      - VeeZero - fixed in this cipher");
>       Ada.Text_IO.New_Line;
>       Ada.Integer_Text_IO.Put(Item => T_1, Width => 4);
>       Ada.Integer_Text_IO.Put(Item => T_2, Width => 8);
>       Ada.Integer_Text_IO.Put(Item => T_3, Width => 8);
>       Ada.Text_IO.Put
>         (Item => "      - VeeOne - fixed in this cipher.");
>       Ada.Text_IO.New_Line;
>       Compute_Normal;
>       Ada.Integer_Text_IO.Put(Item => Normal(1), Width => 4);
>       Ada.Integer_Text_IO.Put(Item => Normal(2), Width => 8);
>       Ada.Integer_Text_IO.Put(Item => Normal(3), Width => 8);
>       Ada.Text_IO.Put(Item => "      - Normal vector -  fixed in this cipher");
>       Ada.Text_IO.New_Line;
>       n :=(Character'Pos(NextChar));
>       Ada.Integer_Text_IO.Put(Item => n, Width =>12);
>       Ada.Text_IO.Put
>         (Item => "              - face value 'n' of current plaintext in ASCII");
>       Ada.Text_IO.New_Line;
>       n := Number(Character'Pos(NextChar));  -- renumbered by Alice
>       Ada.Integer_Text_IO.Put(Item => n, Width =>12);
>       Ada.Text_IO.Put
>         (Item => "              - rendered value of 'n'in the encryption alphabet");
>       Compute_Position_Vector(Number => n);
>       Ada.Text_IO.New_Line;
>       Ada.Integer_Text_IO.Put(Item => Pn(1), Width => 8);
>       Ada.Integer_Text_IO.Put(Item => Pn(2), Width => 8);
>       Ada.Integer_Text_IO.Put(Item => Pn(3), Width => 8);
>       Ada.Text_IO.Put(Item => "  - Position vector ('Pn') for this 'n'. ");
>       Ada.Text_IO.New_Line;
>       Ada.Integer_Text_IO.Put(Item => Hash_2(Count), Width => 8);
>       Ada.Integer_Text_IO.Put(Item => Hash_11(Count), Width => 8);
>       Ada.Integer_Text_IO.Put(Item => Hash_12(Count), Width => 8);
>       Ada.Text_IO.Put
>         (Item => "  - Change-of-origin vector to be given to this Pn item");
>       Ada.Text_IO.New_Line;
>       FOR I IN 1 .. 3 LOOP
>          W(I):= Compose_CipherText_Items( Numin => I);
>          Ada.Integer_Text_IO.Put(File => OutData, Item =>  W(I));
>       END LOOP;
>       Ada.Integer_Text_IO.Put( Item =>  W(1), Width => 9);
>       Ada.Integer_Text_IO.Put( Item =>  W(2), Width => 8);
>       Ada.Integer_Text_IO.Put( Item =>  W(3), Width => 8);
>       Ada.Text_IO.Put(Item =>" - Ciphertext for this item of plaintext");
>       Q:= W(1)REM 1000000;
>       I_Num(Q) := I_Num(Q)+1;
>       --  Q:= W(2)REM 1000000;
>       --  I_Num(Q) := I_Num(Q)+1;
>       --  Q:= W(3)REM 1000000;
>       --  I_Num(Q) := I_Num(Q)+1;
>       --  Ada.Text_IO.New_Line;
>       --  Ada.Integer_Text_IO.Put(Item => AllTold, Width =>4);
>       --  Ada.Integer_Text_IO.Put(Item => Total, Width =>8);
>       --  Ada.Integer_Text_IO.Put(Item => InToto, Width =>8);
>       --  Ada.Text_IO.Put(Item => "      - Compares 'AllTold','Total','InToto' integrators'");
>       Line_Number:= Line_Number+1;
>       Ada.Text_IO.New_Line(1);
>       Ada.Text_IO.Put(Item => "                          - Character number ");
>       Ada.Integer_Text_IO.Put(Item => Line_Number, Width => 1);
>       Ada.Text_IO.New_Line(1);
>       IF Line_Number REM 12 = 0 THEN
>          Ada.Text_IO.New_Line(1);
>          Ada.Text_IO.Put(Item => "                       ");
>          Ada.Text_IO.Put(Item => " # - press any key/return to continue > ");
>          Ada.Text_IO.Get(Item => View);
>       END IF;
>       Ada.Text_IO.New_Line;
>       Ada.Text_IO.Put(Item => "  ---------------------------------------------------------------------------");
>    END LOOP;
>    Ada.Text_IO.Close(File => Outdata);
>    Time_Ex_2;  -- time at end
> end Obyrne_1;
> 
> This gives the following compilation errors:
> 
> obyrne_1.adb:6:04: "Time_Ex_1" is undefined
> obyrne_1.adb:7:04: "Count" is undefined (more references follow)
> obyrne_1.adb:7:14: "Phi" is undefined (more references follow)
> obyrne_1.adb:8:04: "Resets" is undefined (more references follow)
> obyrne_1.adb:9:04: "Total" is undefined (more references follow)
> obyrne_1.adb:10:04: "NextChar" is undefined (more references follow)
> obyrne_1.adb:11:04: "Line_Number" is undefined (more references follow)
> obyrne_1.adb:13:28: "Sentinel" is undefined
> obyrne_1.adb:15:21: "Span" is undefined
> obyrne_1.adb:20:07: "Ada" is undefined (more references follow)
> obyrne_1.adb:20:07: missing "with Ada.Text_IO;"
> obyrne_1.adb:21:18: "Counter" is undefined (more references follow)
> obyrne_1.adb:23:07: "Image" is undefined
> obyrne_1.adb:51:07: "Compute_Normal" is undefined (more references follow)
> obyrne_1.adb:75:07: "n" is undefined (more references follow)
> obyrne_1.adb:80:12: "Number" is undefined
> obyrne_1.adb:84:07: "Compute_Position_Vector" is undefined
> obyrne_1.adb:98:10: "W" is undefined (more references follow)
> obyrne_1.adb:98:17: "Compose_CipherText_Items" is undefined
> obyrne_1.adb:105:07: "Q" is undefined (more references follow)
> obyrne_1.adb:106:19: "I_Num" is undefined (more references follow)
> obyrne_1.adb:131:04: "Time_Ex_2" is undefined
> 
> Until these errors are fixed, we can't help you, because we can't tell
> where the problem is.
> 
> See the FIXME: comments for more detailed advice on how to change the
> code.
> 
> Your first post said there was an "if" statement that did not work, so
> the code you present should contain just that "if" statment, together
> with the required declarations, and some Text_IO.Put_lines to
> demonstrate the problem.
> 
> In addition, please state clearly what the problem is. The only thing
> you've said so far is "it doesn't work". That usually means "it doesn't
> do what I want it to do". Since we don't know what you want it to do, we
> can't help.
> 
> You could say something like:
> 
>     I expect line 23 to output "23", but it outputs "42".
> 
> -- 
> -- Stephe

Hi Stephe,

I am overwhelmed with the volume of help from everybody. With hindsight I should have taken more care in presenting my problem. Now that I know the drill I will be more careful in the future.  Part of my problem is in not learning Ada properly. I go for problem solving by alternative methods instead of fine tuning the method in hand.

In passing, I note that professor M.B. Feldman is posting here also today.  I cannot overstate the email help this man gave me in getting stared with Ada-95 - thanks again Professor - your book was and is excellent (if you can get a used copy).

adacrypt.