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  4. Interesting technique used in some Legacy code!

Interesting technique used in some Legacy code!

Scheduled Pinned Locked Moved The Weird and The Wonderful
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  • D Offline
    D Offline
    DeathByChocolate
    wrote on last edited by
    #1

    This was at the top of the code:

    #define 300 1
    #define 100 0

    I'm amazed that the compiler even accepted it! :rolleyes:

    "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

    N Kornfeld Eliyahu PeterK OriginalGriffO B P 6 Replies Last reply
    0
    • D DeathByChocolate

      This was at the top of the code:

      #define 300 1
      #define 100 0

      I'm amazed that the compiler even accepted it! :rolleyes:

      "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

      N Offline
      N Offline
      Nagy Vilmos
      wrote on last edited by
      #2

      Wow! You broke maths!

      D 1 Reply Last reply
      0
      • D DeathByChocolate

        This was at the top of the code:

        #define 300 1
        #define 100 0

        I'm amazed that the compiler even accepted it! :rolleyes:

        "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

        Kornfeld Eliyahu PeterK Offline
        Kornfeld Eliyahu PeterK Offline
        Kornfeld Eliyahu Peter
        wrote on last edited by
        #3

        No problem with the compiler, but that code should give a one-way ticket to the developer...

        I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

        "It never ceases to amaze me that a spacecraft launched in 1977 can be fixed remotely from Earth." ― Brian Cox

        D 1 Reply Last reply
        0
        • N Nagy Vilmos

          Wow! You broke maths!

          D Offline
          D Offline
          DeathByChocolate
          wrote on last edited by
          #4

          It wasn't me! :rolleyes: :laugh: :laugh: I couldn't believe it compiled, but it must have. I guess there was a bug in the compiler that let it through because now it doesn't. :rolleyes:

          "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

          1 Reply Last reply
          0
          • Kornfeld Eliyahu PeterK Kornfeld Eliyahu Peter

            No problem with the compiler, but that code should give a one-way ticket to the developer...

            I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

            D Offline
            D Offline
            DeathByChocolate
            wrote on last edited by
            #5

            Kornfeld Eliyahu Peter wrote:

            that code should give a one-way ticket to the developer...

            He's gone! :-D ... but that means someone else has to sort it out! :( :rolleyes:

            "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

            Kornfeld Eliyahu PeterK 1 Reply Last reply
            0
            • D DeathByChocolate

              Kornfeld Eliyahu Peter wrote:

              that code should give a one-way ticket to the developer...

              He's gone! :-D ... but that means someone else has to sort it out! :( :rolleyes:

              "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

              Kornfeld Eliyahu PeterK Offline
              Kornfeld Eliyahu PeterK Offline
              Kornfeld Eliyahu Peter
              wrote on last edited by
              #6

              It shouldn't take more than one block of chocolate to you :laugh:

              I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

              "It never ceases to amaze me that a spacecraft launched in 1977 can be fixed remotely from Earth." ― Brian Cox

              D 1 Reply Last reply
              0
              • Kornfeld Eliyahu PeterK Kornfeld Eliyahu Peter

                It shouldn't take more than one block of chocolate to you :laugh:

                I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

                D Offline
                D Offline
                DeathByChocolate
                wrote on last edited by
                #7

                If only consumption of chocolate would fix that code! :rolleyes:

                "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

                1 Reply Last reply
                0
                • D DeathByChocolate

                  This was at the top of the code:

                  #define 300 1
                  #define 100 0

                  I'm amazed that the compiler even accepted it! :rolleyes:

                  "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

                  OriginalGriffO Offline
                  OriginalGriffO Offline
                  OriginalGriff
                  wrote on last edited by
                  #8

                  Well, the good news is it wasn't hidden away in a header file... :omg: If it's any consolation, A FORTRAN compiler I used to work with years, and years ago would accept a constant value as a function parameter, and let you change it at run time. I can't remember FORTRAN syntax any more but it would be similar to:

                  void MyMethod (ref int i)
                  {
                  i = 666;
                  }
                  ...
                  Console.WriteLine(42);
                  MyMethod(42);
                  Console.WriteLine(42);

                  Would happily print: 42 666

                  Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                  "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                  "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                  M Kornfeld Eliyahu PeterK M 3 Replies Last reply
                  0
                  • OriginalGriffO OriginalGriff

                    Well, the good news is it wasn't hidden away in a header file... :omg: If it's any consolation, A FORTRAN compiler I used to work with years, and years ago would accept a constant value as a function parameter, and let you change it at run time. I can't remember FORTRAN syntax any more but it would be similar to:

                    void MyMethod (ref int i)
                    {
                    i = 666;
                    }
                    ...
                    Console.WriteLine(42);
                    MyMethod(42);
                    Console.WriteLine(42);

                    Would happily print: 42 666

                    Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                    M Offline
                    M Offline
                    Marco Bertschi
                    wrote on last edited by
                    #9

                    You surely meant to write

                    void MyMethod (const int i)
                    {
                    i = 666;
                    }

                    The console is a black place

                    OriginalGriffO 1 Reply Last reply
                    0
                    • OriginalGriffO OriginalGriff

                      Well, the good news is it wasn't hidden away in a header file... :omg: If it's any consolation, A FORTRAN compiler I used to work with years, and years ago would accept a constant value as a function parameter, and let you change it at run time. I can't remember FORTRAN syntax any more but it would be similar to:

                      void MyMethod (ref int i)
                      {
                      i = 666;
                      }
                      ...
                      Console.WriteLine(42);
                      MyMethod(42);
                      Console.WriteLine(42);

                      Would happily print: 42 666

                      Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                      Kornfeld Eliyahu PeterK Offline
                      Kornfeld Eliyahu PeterK Offline
                      Kornfeld Eliyahu Peter
                      wrote on last edited by
                      #10

                      OriginalGriff wrote:

                      I can't remember FORTRAN syntax any more

                      Getting old?!

                      I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

                      "It never ceases to amaze me that a spacecraft launched in 1977 can be fixed remotely from Earth." ― Brian Cox

                      OriginalGriffO 1 Reply Last reply
                      0
                      • M Marco Bertschi

                        You surely meant to write

                        void MyMethod (const int i)
                        {
                        i = 666;
                        }

                        The console is a black place

                        OriginalGriffO Offline
                        OriginalGriffO Offline
                        OriginalGriff
                        wrote on last edited by
                        #11

                        No, that implies the wrong thing. The compiler stored all it's constant values in memory locations, so it could happily pass a reference (or more accurately in those days a machine code pointer) to a constant value and it would act like a variable. Total PITA to debug when you met it for the first time: and a hanging offence to leave in production code...

                        Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                        "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                        "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                        F C 2 Replies Last reply
                        0
                        • Kornfeld Eliyahu PeterK Kornfeld Eliyahu Peter

                          OriginalGriff wrote:

                          I can't remember FORTRAN syntax any more

                          Getting old?!

                          I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

                          OriginalGriffO Offline
                          OriginalGriffO Offline
                          OriginalGriff
                          wrote on last edited by
                          #12

                          I haven't used it for years - and archive retrieval is a lot slower than online storage! :laugh:

                          Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                          "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                          "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                          B 1 Reply Last reply
                          0
                          • OriginalGriffO OriginalGriff

                            I haven't used it for years - and archive retrieval is a lot slower than online storage! :laugh:

                            Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                            B Offline
                            B Offline
                            Bernhard Hiller
                            wrote on last edited by
                            #13

                            OriginalGriff wrote:

                            archive retrieval

                            Magnetic tape at 300 baud? Does the tape reader still work with current Windows?

                            OriginalGriffO 1 Reply Last reply
                            0
                            • D DeathByChocolate

                              This was at the top of the code:

                              #define 300 1
                              #define 100 0

                              I'm amazed that the compiler even accepted it! :rolleyes:

                              "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

                              B Offline
                              B Offline
                              Bernhard Hiller
                              wrote on last edited by
                              #14

                              As a side-effect, wouldn't it change 30000 to 0 via 30000 -> 100 -> 0?

                              1 Reply Last reply
                              0
                              • D DeathByChocolate

                                This was at the top of the code:

                                #define 300 1
                                #define 100 0

                                I'm amazed that the compiler even accepted it! :rolleyes:

                                "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

                                P Offline
                                P Offline
                                phil o
                                wrote on last edited by
                                #15

                                What happens then when you try to divide a number by 100? Just curious ^^

                                There are two kinds of people in the world: those who separate humankind in two distinct categories, and those who don't. "I have two hobbies: breasts." DSK

                                D 1 Reply Last reply
                                0
                                • B Bernhard Hiller

                                  OriginalGriff wrote:

                                  archive retrieval

                                  Magnetic tape at 300 baud? Does the tape reader still work with current Windows?

                                  OriginalGriffO Offline
                                  OriginalGriffO Offline
                                  OriginalGriff
                                  wrote on last edited by
                                  #16

                                  I wish! This is the long term storage between my ears we are talking about here... :laugh: I just wish I could find a way to re-index it occasionally ;)

                                  Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                                  "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                                  "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

                                  1 Reply Last reply
                                  0
                                  • P phil o

                                    What happens then when you try to divide a number by 100? Just curious ^^

                                    There are two kinds of people in the world: those who separate humankind in two distinct categories, and those who don't. "I have two hobbies: breasts." DSK

                                    D Offline
                                    D Offline
                                    DeathByChocolate
                                    wrote on last edited by
                                    #17

                                    I guess, if you did try to do that, you would get a 'divide by 0 error'. Fortunately its only a small project and neither 100 or 300 were ever used as absolute values. It loaded a int with either 300 or 100 (ie 0 or 1) then later it checked to see if that int was equal to 300 or 100 (ie 0 or 1), so it did work but not a technique I would recommend! :rolleyes: :-D

                                    "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

                                    P 1 Reply Last reply
                                    0
                                    • D DeathByChocolate

                                      I guess, if you did try to do that, you would get a 'divide by 0 error'. Fortunately its only a small project and neither 100 or 300 were ever used as absolute values. It loaded a int with either 300 or 100 (ie 0 or 1) then later it checked to see if that int was equal to 300 or 100 (ie 0 or 1), so it did work but not a technique I would recommend! :rolleyes: :-D

                                      "State acheived after eating too many chocolate-covered coconut bars - bountiful" Chris C-B

                                      P Offline
                                      P Offline
                                      phil o
                                      wrote on last edited by
                                      #18

                                      Me neither :)

                                      There are two kinds of people in the world: those who separate humankind in two distinct categories, and those who don't. "I have two hobbies: breasts." DSK

                                      1 Reply Last reply
                                      0
                                      • OriginalGriffO OriginalGriff

                                        No, that implies the wrong thing. The compiler stored all it's constant values in memory locations, so it could happily pass a reference (or more accurately in those days a machine code pointer) to a constant value and it would act like a variable. Total PITA to debug when you met it for the first time: and a hanging offence to leave in production code...

                                        Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                                        F Offline
                                        F Offline
                                        Freak30
                                        wrote on last edited by
                                        #19

                                        Changing the value of a literal for subsequent uses of the same literal is pure evil. Who could have ever thought, it was a good idea to implement constants that way? :omg: Was it possibly done to keep the image size of the executable small?

                                        The good thing about pessimism is, that you are always either right or pleasently surprised.

                                        OriginalGriffO 1 Reply Last reply
                                        0
                                        • F Freak30

                                          Changing the value of a literal for subsequent uses of the same literal is pure evil. Who could have ever thought, it was a good idea to implement constants that way? :omg: Was it possibly done to keep the image size of the executable small?

                                          The good thing about pessimism is, that you are always either right or pleasently surprised.

                                          OriginalGriffO Offline
                                          OriginalGriffO Offline
                                          OriginalGriff
                                          wrote on last edited by
                                          #20

                                          Probably - everything was kept small in those days: we didn't have anywhere near as much disk space as you do cache! If I remember rightly, it was a GEC4070[^] - so the main memory would have been 512Kb - and a dozen users using it...

                                          Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952) Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)

                                          "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
                                          "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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