Contracts in Smart Pascal

Contracts are now partially supported: ensure, require and old are available and use the same syntax as Prism contracts, inheritance is supported.
the implies operator is now supported, “a implies b” is equivalent to “(not a) or b”, or in other words, it is false only if a is true and b is false.
Assert() is supported, and will trigger EAssertionFailed in case of, well, an assertion failure. A compiler option has been added to control the generation of assertions.
Exception now has a StackTrace method, which will return a textual stacktrace script-side. Runtime errors now also include a stack trace, and new Delphi-side methods provide access to even more details.
the in operator has been extended to allow class overloading, f.i. you can now use “if (aString in someStringList) then…”, the not in form is also supported.

Pas2JS pascal source code


function IncFunc(Val, delta: Integer): Integer;
begin
  Result := Val + delta;
  ensure 
  Result = old Val + 1;
end;

procedure IncProc(var Val: Integer; delta: Integer);
begin
  Val += delta;
  ensure 
  Val = old Val + 1;
end;

{ main.pas }
  var
    v: Integer = 1;

Begin
  v := IncFunc(v, 1);
  Writeln(v);
  IncProc(v, 1);
  Writeln(v);

  try
    v := IncFunc(v, 2)
  except
    on E: Exception do
      Writeln(E.Message);
  end;
  try
    IncProc(v, 2)
  except
    on E: Exception do
      Writeln(E.Message);
  end;
  Writeln(v); // 2  3  7


      var v = {};
      v.v = 1;
      v.v = IncFunc(v.v,1);
      WriteLn(v.v);
      IncProc(v,1);
      WriteLn(v.v);
      try {
         v.v = IncFunc(v.v,2);
      } catch ($e) {
         var E = $W($e);
         WriteLn(E.FMessage)      }
      try {
         IncProc(v,2);
      } catch ($e) {
         var E$1 = $W($e);
         WriteLn(E$1.FMessage)      }
      WriteLn(v.v);

function IncProc(Val, delta) {
   var old$1 = Val.v;
   Val.v+=delta;
};
function IncFunc(Val$1, delta$1) {
   var Result = 0;
   var old$1$1 = Val$1;
   Result = Val$1+delta$1;
   return Result
};

Contracts in Smart Pascal | ensure | require | old