Thank's I will surely check it out!
Ad well... i get that impression even though I start the game with the BNW (including my own coutnry - Poland - in this expansion was one of the first thing that actually catch my attention and make me want to try the game). Strangely enough I get a feeling that through some "silent" (by that I mean I didn't actually notice or at least didn't remember noticing any) update just BNW change to much less modder-friendly (for example I remember that I could completely freely change the city range both in matter of acquireable by culture board expansion and being workable - for playing as one city civ even 5 tiles could be to few in more advanced stage of the game... but now it seems to be impossible any longer - I don't get who could come up with such a stupid update which even in some sense break the game to me - by that I mean that I can't enjoy playing it so much like I had before)
Also as much as I understand faith wasn't the orginal yield... (though personally as I started playing with BNW from the very beginning even the elements from expansion like faith or even tourism are for me as native to the game like food or production - but that are feeling more tha facts and I know that) I can't agree with sentence
There's no single definition here that can be used across the board and coded at any level that can adapt so far as what to do with Yield-X
Actually You even kind of write negation Yourself - all the yields have one thing in common: they are some statistic, numeric feature of the tile (here I mean all: base yield of the terrain, yield from features and improvements) specialist or building, kind of countable profit a city can get if use that tile/have working specialist/have building builded.
Which city gets and then... well what is done with that deppends on yield type:
- added to city reserve in case of food
- added (or redirceted) to empire reserve in case of gold, faith or culture (which all are some king of a reserve, just the way the reserve is used differs) - similarly for tourism but here with this split to all other players
- added to current city production proces in case of production
- added to current reserch in case of science
That way it can be adapted to any way of spending those points - it's just matter of being using directly by the city or being send further to some game mechanics. And at the point of being given to the city it could also by easily modifie by some yieldmodifiers.
Actually the same abstraction could apply also to great people points. And as much as it plainly wasn't implemented in the game that way but it could be, and I even dare say it should. At least from modder perspective. Well actually not only because (if it would be done so from the very beginning) it would also make easier for developers to add new kind of yields.
And as much as that's kinda fruitless reasoning... well maybe it will at least help me to avoid some similar mistakes when I will be creating my own games (yeah I have an ambition of becoming game programmer some day)... but for now I just think I should learn how to mess with the dll modding... but as noticed - it has the disadvantage of being potentially less compatible (and that's the way I wanted to come up with a way that don't need any dll moding but just some alternation in XML or at worst lua script or other relatively easy overwriting the code - intentionally without breaking any compatibilities)