Re: [freeciv-dev] Unit obsolescence vs Civ2

[David Pfitzner <dwp@xxxxxxxxxxxxxx>]

Bobby D. Bryant wrote:
> 
> I notice that in FreeCiv you must specify unit obsolecence in terms of
> another unit type, whereas in Civ2 you specify it in terms of a tech
> advance.  Was the change deliberate, or did it just slip into the system
> along the way?

I think the reason it is done that way is that unit.obsolete_by
is also used for unit upgrades, in terms of which unit you can
upgrade to.   For example in the following case...

> for example, just using Stealth
> rather than Stealth Fighter to obsolete the Fighter.  There is always a
> 1:1 mapping between new unit types an an enabling technology, but not
> vice versa.)

...freeciv needs to know that Fighters are upgradeable to Stealth 
Fighters, and not to Stealth Bombers.

I guess in princple you could have a unit.obsolete_by_tech entry, 
but since it isn't currently used it hasn't been implemented...
(I expect implementing it now would not be entirely trivial, since 
there are probably various places in the code where it is assmed 
that obsolete implies upgradeable and vice versa.)

Regards,
-- David