Question

I have a library of functions contained in a delphi unit which we shall call UtilitiesU. Some of these functions are just helper functions that are only used inside UtilitiesU. I would like to limit the scope of these functions to UtilitiesU. These are the methods that I know of for doing this:

1. Remove the declaration from the interface and move the function before its dependents in the implementation – messy, counter-intuitive order of function definitions, not always possible if there is e.g. mutual dependency
2. Put all the functions into a static class (ala Java) and make them public or private as appropriate – too much boilerplate, convoluted
3. Declare the helper functions local to the functions in which they are used – same problems as point 1

Ideally, I would like to do it the C/C++ way – that is, declare them as static in the implementation section. Is this possible? Is there a better way?

Answer 1

I would do:

Remove the declaration from the
interface and move the function before
its dependents in the implementation –
messy, counter-intuitive order of
function definitions, not always
possible if there is e.g. mutual
dependency

Btw, theres not way of declaring a static class in delphi as you do in other languages. Only var and methods can be static, not the entire class.

There are other 3 ways

1 – You can create a class an put all the helper code on it on its private section (maybe statics methods) and use it inside the UtilitiesU unit. Bu I would not go for it, the 1 method you wrote is the best, I think.

2 – You can separe all your helper code in another unit, lest call it UtilitiesHelper.

3 – You can mix 1 and 2, but using protected methods. Then you can easily hack the helper class in your UtilitiesU unit. Example:

In the UtilitiesHelper unit

TUtilitiesHelper = class
protected
   //all your methods here
end;

In the UtilitiesU unit

TUtilitiesHelperHack = class(TUtilitiesHelper)
end;

With that you can access protected methods. But I dont recommend it also.

EDIT

As Ken said, you can use:

implementation

procedure ShowMe;forward;

I just tested this myself and it worked. (thats new to me also, thanks Ken).