procedure delete(var s : shortstring;index : SizeInt;count : SizeInt);
begin
  if index<=0 then
     exit;
  if (Index<=Length(s)) and (Count>0) then
   begin
     if Count>length(s)-Index then
      Count:=length(s)-Index+1;
     s[0]:=Chr(length(s)-Count);
     if Index<=Length(s) then
      Move(s[Index+Count],s[Index],Length(s)-Index+1);
   end;
end;

procedure Move(const source;var dest;count:SizeInt);[public, alias: 'FPC_MOVE'];assembler;nostackframe;
asm
  cmp     ecx,SMALLMOVESIZE
  ja      @Large
  cmp     eax,edx
  lea     eax,[eax+ecx]
  jle     @SmallCheck
@SmallForward:
  add     edx,ecx
  jmp     SmallForwardMove_3
@SmallCheck:
  je      @Done {For Compatibility with Delphi's move for Source = Dest}
  sub     eax,ecx
  jmp     SmallBackwardMove_3
@Large:
  jng     @Done {For Compatibility with Delphi's move for Count < 0}
  cmp     eax,edx
  jg      @moveforward
  je      @Done {For Compatibility with Delphi's move for Source = Dest}
  push    eax
  add     eax,ecx
  cmp     eax,edx
  pop     eax
  jg      @movebackward
@moveforward:
  jmp     dword ptr fastmoveproc_forward
@movebackward:
  jmp     dword ptr fastmoveproc_backward {Source/Dest Overlap}
@Done:
end;

j := Low(S); 
for i := Low(S) to LS do
  if Good(S[i]) then begin 
    S[j] := S[i];  
    Inc(j);
  end;
LS := j;

procedure print_arr(const arr: array of integer; n: integer);
var i: integer;
begin
  write('<', n:2, '> ');
  for i := 0 to pred(n) do write(arr[i]:3);
  writeln;
end;

const
  size = 10;

var
  arr: array[1 .. size] of integer;
  real_size: integer;

  i, j: integer;
  b: boolean;

begin
  real_size := size;
  for i := 1 to size do
  begin
    arr[i] := i mod 2;
  end;

  print_arr(arr, real_size);

  j := Low(arr);
  for i := Low(arr) to real_size do
    if arr[i] <> 0 then { Good(X) => (X <> 0) }
    begin
      arr[j] := arr[i];
      Inc(j);
    end;
  real_size := j;

  print_arr(arr, real_size);
end.

Running "f:\programs\pascal\tst_fq.exe "
<10>   1  0  1  0  1  0  1  0  1  0
< 6>   1  1  1  1  1  0

j := Low(S); 
for i := Low(S) to High(S) do
  if Good(S[i]) then begin 
    S[j] := S[i];  
    Inc(j);
  end;
LS := j - Low(S);

procedure print_arr(const arr: array of integer; n: integer);
var i: integer;
begin
  write('<', n:2, '> ');
  for i := 0 to pred(n) do write(arr[i]:3);
  writeln;
end;

const
  size = 10;
  s = -56;

var
  arr: array[s .. s+size-1] of integer;
  real_size: integer;

  i, j: integer;
  b: boolean;

begin
  randomize;

  real_size := size+s-1;
  for i := s to real_size do
  begin
    arr[i] := random(3);
  end;

  print_arr(arr, real_size-s+1);

  j := Low(arr);
  for i := Low(arr) to real_size do
    if arr[i] <> 0 then { Good(X) => (X <> 0) }
    begin
      arr[j] := arr[i];
      Inc(j);
    end;
  real_size := j - 1;

  print_arr(arr, real_size-s+1);
end.