delphi - Loosen "Local procedure/function assigned to procedure variable" restriction gracefully

Question

Consider the following test-case:

{ CompilerVersion = 21 }
procedure Global();

  procedure Local();
  begin
  end;

type
  TProcedure = procedure ();
var
  Proc: TProcedure;
begin
  Proc := Local;  { E2094 Local procedure/function 'Local' assigned to procedure variable }
end;

At line 13 compiler emits message with ERROR level, prohibiting all of the cases of such local procedures usage. "Official" resolution is to promote Local symbol to the outer scope (ie: make it a sibling of Global) which would have negative impact on code "structuredness".

---

I'm seeking the way to circumvent it in most graceful manner, preferably causing compiler to emit WARNING level message.

Answer 1

Your best bet is to declare it as reference to procedure using the new anonymous methods feature and then you can keep everything nicely encapsulated.

type
  TProc = reference to procedure;

procedure Outer;
var
  Local: TProc;
begin
  Local := procedure
    begin
      DoStuff;
    end;
  Local;
end;

This gets around the issues that Mason describes by capturing any variables local to the anonymous function.