Re: Lua Tutor (Delphi + Lua)

[Jilani Khaldi <jilani.khaldi1@...>]

> Beat me. Suggest to post your code the way I did earlier. Lua folks would be
> able to answer. I ain't no pro like them! I just did the implementation.
> Like you, I am still learning.
>  
// Call add_xy() from Delphi:
function call_add_xy(L: Plua_State; x, y: Double): Double;
begin
  // Push functions and arguments:
  lua_getglobal(L, 'add_xy');  // Function to be called.
  lua_pushnumber(L ,x);        // Push 1st argument.
  lua_pushnumber(L, y);        // push 2nd argument.

  // Do the call (2 arguments, 1 result):
  if lua_pcall(L, 2, 1, 0) <> 0 then
  begin
    // Handle error here.
  end;

  // Retrieve result:
  if not lua_isnumber(L, -1) then
  begin
    // Handle error here.
  end;
  Result := lua_tonumber(L, -1);

  // pop returned value:
  lua_pop(L, 1);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
 L: Plua_State;
 FName: PChar;
 x, y, R: double;
 st: string;
 pc: PChar;
begin
 FName := 'exp1.lua';
 L := lua_open();
 luaopen_base(L);
//  luaopen_io(L); (*)
 luaL_loadfile(L, FName);
 lua_call(L, 0, 0);
 x := 3.14159;
 y := 2.71828;
 R := call_add_xy(L,x,y);
 st := Format('pi + e = %1.5f', [R]);
 memo1.Lines.Add(st);
 lua_close(L);
end;

exp1.lua file contains:

function add_xy(x, y)
 return (x + y)
end

(*): this line gives an "access violation" if the program is run from 
Delphi IDE with lua5.1.dll, but not with lua5.0.dll

jk