[Freeciv-Dev] Re: (PR#12930) RFC: generalizing output types in effects

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12930 >

Benoit Hudson wrote:

> Do we need more than 2-d?  It wouldn't be hard to go for 3, but I can't
> think why we would want to.

We have one 3d effect: EFT_XXX_BONUS and EFT_XXX_BONUS_2.

> We could also use just one function, at the cost of some checking:
>     get_city_bonus(const struct city *pcity, enum effect_type, ...)
> a la fcntl.  This may be a bad idea, I'm not sure.
> 
> I'm not sure why this solution is particularly complicated, as compared
> to the making the output type a requirement (which is... interesting).

When the requirement solution occurred to me, I immediately rejected it.
 The output type isn't a requirement, it's a parameter!  But as I kept
looking a the other situations where this comes up (specialist bonuses,
unit bonuses) I realized that this distinction is very blurry.

Consider (simplified registry format):

  [effect_factory]
  name = "Output_Bonus", "Shield"
  reqs = {
    "Building", "Factory"
  }

  [effect_factory]
  name = "Output_bonus"
  reqs = {
    "Building", "Factory"
    "Output_Type", "Shield"
  }

you'd probably say the first one makes a lot more sense.  But now consider:

  [effect_libraries_make_scientists_smarter]
  name = "OUTPUT_INC_SPECIALIST", "Science", "Scientist"
  reqs = {
    "Building", "Library"
  }

  [effect_libraries_make_scientists_smarter]
  name = "OUTPUT_INC_SPECIALIST", "Science"
  reqs = {
    "Building", "Library"
    "Specialist", "Scientist"
  }

  [effect_libraries_make_scientists_smarter]
  name = "OUTPUT_INC_SPECIALIST", "Scientist"
  reqs = {
    "Building", "Library"
    "Output_Type", "Science"
  }

  [effect_libraries_make_scientists_smarter]
  name = "OUTPUT_INC_SPECIALIST"
  reqs = {
    "Building", "Library"
    "Specialist", "Scientist"
    "Output_Type", "Science"
  }

is there one of these forms that is preferred?  And what about:

  [effect_magellans]
  name = "MOVE", "Sea"
  reqs = {
    "Building", "Magellan's"
  }

  [effect_magellans]
  name = "MOVE"
  reqs = {
    "Building", "Magellan's"
    "UnitClass", "Sea"
  }

is there a preferred form here?

-jason