The Anti-Case campaign

Some time ago, Nick and Malcolm drew our attention on a site which promote an anti-if campaign. Well, I don’t know how much that campaign is interesting for us, because, sincerely, I don’t see any time soon the if construction removed from programming languages.

But I will propose another campaign which I think is much more stringent for Delphi developers… It is anti Case campaign. And to be very clear, is against Case structure in the form in which is implemented now.

The idea struck when, having my previous experience with Class Signatures, I saw Jolyon’s post about using of absolute keyword. The first reaction was “Hey, my solution is better than this (safer – checks at compile time, much clearer code etc.) but it is a language improvement (requires support from the compiler)”. But because for us, mere mortals, this isn’t so easy to get, I tried to make Jolyon’s code cleaner. I was very frustrated (again) because in a perfect world, one should just write:

procedure Foo(aObject: TObject);
begin
  case aObject.ClassType of
    TEdit:
    TMemo:
    TLabel:
  else
    //...
  end;
end;

or

procedure Foo(aObject: TObject);
begin
  case aObject of
    myEdit:
    myMemo:
    myLabel:
  else
    //...
  end;
end;

In fact there are integers, no? (An ‘ordinal’ type…)
…and of course, let us just skip over the advantages of the above code compared with the spaghetti code generated by the if approach.

Pushing things further, case, even if its very fast, nowadays is quite limited for the programming needs of a programmer in the winter of 2009 (yeah, I’m looking a little bit forward, but just a little, you know).

No strings, no objects, no classes. No floating-point, no records, no variants. No interfaces, no custom types, no nothing. Did I miss something?

In short, I propose to enhance the actual ‘Case’ structure to support every entity which has the = (equal) operator defined.

Your task?

Easy! Vote & Comment!