Smart pascal source code


type
  TStringProc = procedure(s: String);

procedure Test(s: String; f: TStringProc = nil);
begin
  if Assigned(f) then
    f(s)
  else
    WriteLn(s);
end;

procedure WriteLnWrap(s: String);
begin
  WriteLn('wrap: ');
  WriteLn(s);
end;

Test('Hello');
Test('World', nil);
Test('Byebye', WriteLnWrap);
Test('World', @WriteLnWrap);

var
p := @WriteLnWrap;

Test('Hello', p);
p := nil;
Test('Again', p);

{<<< RESULT - CONSOLE LOG >>>
-----------------------------
Hello
World
wrap: Byebye
wrap: World
wrap: Hello
Again
-----------------------------
{<<<<<<<<< THE END >>>>>>>>>}

var TObject={
	$ClassName: "TObject",
	$Parent: null,
	ClassName: function (s) { return s.$ClassName },
	ClassType: function (s) { return s },
	ClassParent: function (s) { return s.$Parent },
	$Init: function () {},
	Create: function (s) { return s },
	Destroy: function (s) { for (var prop in s) if (s.hasOwnProperty(prop)) delete s.prop },
	Destroy$: function(s) { return s.ClassType.Destroy(s) },
	Free: function (s) { if (s!==null) s.ClassType.Destroy(s) }
}
var Exception={
	$ClassName: "Exception",
	$Parent: TObject,
	$Init: function () { FMessage="" },
	Create: function (s,Msg) { s.FMessage=Msg; return s }
}
function $New(c) { var i={ClassType:c}; c.$Init(i); return i }
function $CheckFunc(i,z) { if (i) return i; throw Exception.Create($New(Exception),"Function pointer is nil"+z); }
function WriteLn(value) {
    if (window.console) { window.console.log(value); } };
function WriteLnWrap(s) {
   WriteLn("wrap: ");
   WriteLn(s);
};
function Test(s$1, f) {
   if (f) {
      $CheckFunc(f,"")(s$1);
   } else {
      WriteLn(s$1);
   }
};
var p = null;

/* <<< main JS >>> */

   Test("Hello",null);
   Test("World",null);
   Test("Byebye",WriteLnWrap);
   Test("World",WriteLnWrap);
   p = WriteLnWrap;
   Test("Hello",p);
   p = null;
   Test("Again",p);