[fpc-pascal] List of integers? Any class available in RTL or FCL to help?

[Sven Barth]

Am 14.12.2016 08:09 schrieb "Lars" <noreply at z505.com>:
> A general purpose function that handles multiple types of arrays without
> rewriting the code for each array type looks like this:
>
>     procedure AddItemToArray(
>       const item: {$I T.inc}; var arr: {$I TArr.inc}); overload;
>     var len: integer;
>     begin
>       // below is the same for EVERY type! Reuse, Reuse!
>       len:= length(arr);
>       setlength(arr, len+1);
>       arr[len]:= item;
>     end;
>
> Where $I T.inc defines the type being used.

Same code with 3.1.1's generics in non-Delphi mode:

=== code begin ===

generic procedure AddItemToArray<T>(
      const item: T; var arr: specialize TArray<T>); overload;
    var len: integer;
    begin
      // below is the same for EVERY type! Reuse, Reuse!
      len:= length(arr);
      setlength(arr, len+1);
      arr[len]:= item;
    end;

// used like this:
specialize AddItemToArray<Longint>(42, myarr);

=== code end ===

> Maybe I reinvented generics. Advantage of this, is no OOP (object
> orientation) required and it therefore works on any procedural code or OOP
> code, not just OOP code alone.  One reason I dislike generics in modern
> languages is that it almost always requires object orientation to be used
> and you cannot program "generally" using procedural style coding. My
> include file parametric polymorphism allows procedural code to be written
> (such as dealing with simple arrays) generally.

FPC supports global generic routines (even in Delphi mode despite Delphi
itself not supporting it).

Regards,
Sven
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