Pointer arithmetics (was: BPCOMPAT v1.10 -released!)

Thu, 23 Oct 1997 11:18:34 +0200 (MEST)

According to Frank Heckenbach:
> Until a (more optimized) version
> of them will be built in, here are some replacements (a bit slower, but
> should be portable and generate no warnings): [...]

Pointer arithmetics is portable and can be used here to speed it up:

    Procedure FillChar ( Var Dest: Void; Count: Integer; C: Char );
  
    Var
      DestArray: tCharArray absolute Dest;
      z: ^Char;

    begin (* FillChar *)
      for z:= @DestArray [ 0 ] to @DestArray [ Count - 1 ] do
        z^:= C;
    end (* FillChar *);

(Similar for `move'.)

BTW, pointer arithmetics ... should GPC allow constructions like

    (*$X+*)

    Var
      p, q: ^Char;

    p:= q + 42;

or only

    p:= succ ( q, 42 ); ?

Personally, I would prefer to allow only the second (Pointer being an
ordinal type) and to consider the first (Pointer + Integer) an error,
but it's technically easier to allow both, so I ask before I remove a
bug somebody might consider a feature. ;-)

Greetings,

    Peter

 Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer
peter.gerwinski@uni-essen.de - http://home.pages.de/~peter.gerwinski/ [971005]
 maintainer GNU Pascal [971001] - http://home.pages.de/~gnu-pascal/ [971005]

Peter Gerwinski (peter@agnes.dida.physik.uni-essen.de)