Re: What is your opinion on Global Objects?

[Hubert <herrdoktor@fumanchu.com>]

On 11/18/2014 19:03 PM, Jeffrey Carter wrote:
> On 11/18/2014 07:50 PM, Hubert wrote:
>> That basically is a vote for global objects. Whether they are accessed through a
>> global variable or some sort of getter function that returns access
>
> Most of us on here are talking about how to do it in Ada. However you do it in
> C++ will be different, because C++ lacks modules. In Ada, there would be no
> functions that return access.
>
> At some point you have some requirements for your game, and somewhere in them is
> something along the lines of "the game will keep track of this, that, and the
> other".
>
> In the design you make from these reqs you decide to meet this req with a DB
> object. It allows you to add new (Key, Value) pairs, update the value for a key,
> retrieve the value for a key, and delete the pair for a key.
>
> In the Ada implementation, you implement this object as a package:
>
> package Game.DB is
>     procedure Add (Key : in Key_Value; Value : in Data_Value);
>
>     procedure Update (Key : in Key_Value; Value : in Data_Value);
>
>     function Value (Key : in Key_Value) return Data_Value;
>
>     procedure Delete (Key : in Key_Value);
> end Game.DB;
>
> [I'm sure the reality is more complicated. No doubt there are many different
> kinds of (Key, Value) pairs.]
>
> This pkg would be part of a low-level layer in your S/W architecture. Anything
> in higher layers that needs to access the DB can with the pkg and call its
> subprograms.
>
> This is the "Package as Object" pattern in Ada.
>

Ok this is still an access of the global object directly from a 
subprogram. The subprogram then accesses the variable with the data 
ijnternally which is the same as accessing a global object. The data 
object itself is not passed through the parameters of the subprogram 
that uses it.

Sounds like most people are in favor of that method


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