[pjmlp]

Enumerations in Turbo Pascal

    type Colours = (Red, White, Blue);

Enumerations in Go

    type Colours int

    const (
        Red Colours = iota
        White
        Blue
    )

FFI in Turbo Pascal

    function Sin(const num: Integer): Double; external 'ext name';

FFI in Go (requires external help from a C compiler)

   // #include <stdio.h>
   // #include <errno.h>
   import "C"

   func Sin (num uint) float32 {
      return C.sin
   }

Reference parameters in Turbo Pascal with null safety thanks type system

   procedure Swap(var a,b:Integer);
   var
      temp: Integer;
   begin
      temp:=a;
      a:=b;
      b:=temp
   end;

   Swap(x, y)
   Swap(nil, y) { compiler error: Got "Pointer" expected "SmallInt" }

Reference parameters in Go (no type safety via type system, manual testing for nil required)

   func Swap (a *int, b*int) {
      var temp = *a
      *a = *b
      *b = temp
   }

 
   Swap(&x, &y)
   Swap(nil, &y) { runtime error: Invalid memory address or nil pointer dereference }

I was also tempted to move the time scale from 1992 to 2009, but then I wouldn't be able to reproduce the generics from Object Pascal in Go.

Ah, and Turbo Pascal 5.5 was compiling around 34 000 lines/minute in computers whose CPUs were maxed at about 30 MHZ, http://edn.embarcadero.com/article/20803

[YouAreGreat]

The way I remember it, Pascal enums were useless.

Regarding nil safety, did Pascal allow something along the line of the following?

    var x: ^int;
    ...
    x^ := nil;
    Swap(x^, y)

[pjmlp]

Useless to those that didn't understood how to take advantage of them.

They can be used as indexes, range validation, access control in variant records to simulate sum types.

Enumerations are so useless that majority of modern languages have direct support for them.

Yes, it did allow your contrived example, which seldom occurred in practice because proficient Pascal programmers only used pointers when other type safe alternatives weren't possible.