philg hates software: Delphi. Excessive type-bondage.

• From: Phil!Gregory
  Date: 22:08 on 25 Aug 2006
  Subject: Delphi.  Excessive type-bondage.
  
  Allow me to quote from the Delphi help file:
  
    For a variable parameter, the actual argument must be of the exact type
    of the formal parameter. 
  
      procedure SwapBytes(var B1, B2: Byte);
      var
        Temp: Byte;
      begin
        Temp := B1; B1 := B2; B2 := Temp;
      end;
      
      var
        C1, C2: 0..255;     (*Similar to a byte, but NOT identical*)
      begin
        SwapBytes(C1,C2);   (*<-- Error message here*)
      end.
  
    Arguments C1 and C2 are not acceptable to SwapBytes, *although they have
    the exact memory representation and range that a Byte has*.  [Emphasis
    mine.]
  
  Oh, and for the case where I specifically ran into this, typecasting won't
  help.  Apparently when you typecast a variable, the result looks like a
  constant to the compiler so you can't pass it as a variable parameter
  (pass by reference).
  
  
  

• From: peter (Peter da Silva)
  Date: 23:03 on 25 Aug 2006
  Subject: Re: Delphi.  Excessive type-bondage.
  
  >   Arguments C1 and C2 are not acceptable to SwapBytes, *although they have
  >   the exact memory representation and range that a Byte has*.  [Emphasis
  >   mine.]
  
  That's because Delphi is Pascal on drugs.
  
  (well, ALL Pascal is Pascal on drugs, including Wirth's own implementation
   which we used at Berkeley before they replaced pascals with pix, because
   when Pascal's sober it wouldn't even put out for Niklaus)
  
  
  

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