Library to allow mods to request the creation of 'OR nodes' and 'AND nodes' in the technology tree.

OR Nodes

If a mod wants to add a dependency on roboports being unlocked, this is currently not directly possible, as a roboport is unlocked with either researching construction robots or logistics robots.

OR nodes allows the creation of a new 'OR node' (technology) that will be immediately researched when any of its prerequisites have been researched.

Our hypothetical mod then merely needs to depend on the new technology.

local ORNodes = require('__OR-Nodes__.library').init()

local roboport_technology_name = ORNodes.depend_on_item("roboport")

local prerequisites = {
  "some-other-technology"
}

local technology_name = roboport_technology_name[1]
if technology_name then
  table.insert(prerequisites, technology_name)
end

data:extend({
  {
    type = "technology",
    name = "my-nifty-thing",
    prerequisites = prerequisites,
    ...
  }
})

Functions

Returns a technology name that represents that a force:

• depend_on_item(item, item_type, silent) - is able to create the item (or fluid).
• depend_on_any_item(items, silent) - is able to create at least one of the items (or fluids).
• depend_on_recipe(recipe, silent) - is able to craft the recipe.
• depend_on_any_recipe(recipes, silent) - is able to craft at least one of the recipes.
• depend_on_any_technology(technologies, silent) - has researched at least one of the technologies.

There is no depend_on_technology, as that would just return the supplied technology.

AND Nodes

'AND Nodes' are to support the case where the resulting technology is an obvious consequence of the parent technologies being researched. For example, a recipe that loads a gun turret with uranium rounds should not require further research once both turrets and uranium rounds can be created.

local ORNodes = require('__OR-Nodes__.library').init()

local recipe = {
  type = "recipe"
  name = "gun-turret-with-uranium-rounds-magazine",
  ingredients = {
    {"gun-turret", 1},
    {"uranium-rounds-magazine", 10}
  },
  ...
}

local recipe_technology_name = ORNodes.depend_on_all_recipe_ingredients(recipe)

local technology_name = recipe_technology_name[1]
if technology_name then
  local technology = data.raw.technology[technology_name]
  local effects = technology.effects
  if not effects then
    effects = {}
    technology.effects = effects
  end

  recipe.enabled = false

  table.insert(effects, {
    type = "unlock-recipe",
    recipe = "gun-turret-with-uranium-rounds-magazine"
  })
end

Functions

These produce a technology that is automatically researched when all of the prerequisites technologies are researched.

Returns a technology name that represents that a force:

• depend_on_all_recipe_ingredients(recipe, silent) - is able to create all of the items required to craft the recipe.
• depend_on_all_items(items, silent) - is able to create all of the items.
• depend_on_all_recipes(recipes, silent) - is able to craft all of the recipes.
• depend_on_all_technologies(technologies, silent) - has researched all of the technologies.

Allowed inputs

When supplying a list of things (items, recipes, technologies), you may supply the things in several different formats:

• the name of the thing as a string

• for items (or fluids) only, you can supply a table to allow specifying fluids or items.

• { name = 'item-1', type = 'item' }

• { 'fluid-1', 'fluid' }

• { type='fluid, 'fluid-2' }

• you can supply a dictionary of things as keys, with a value indicating the difficulties (normal/expensive) for which those things are required.

-- Requires roboports and iron-gear-wheels on both difficulties, the fluid tender-loving-care for expensive, and the item tough-love in normal
local items = {
  roboport = 3, -- ORNodes.DIFFICULTIES_BOTH
  [{type = 'fluid', 'tender-loving-care'}] = 2, -- ORNodes.DIFFICULTIES_EXPENSIVE
  ['tough-love'] = 1, -- ORNodes.DIFFICULTIES_NORMAL
  'iron-gear-wheel' -- both difficulties if unstated.
}

local technology = ORNodes.depend_on_all_items(items)

Return values

• A list of 1 technology name representing the requested condition
• An empty list when the requested condition is satisfied without any research

On error

• raises an error by default
• returns nil if the silent option is set to true

Limitations

The difficulty support hasn't been well tested.

Can't discover that a technology or recipe is unlocked by script, or that an item is created by a script. You're going to have to determine what technology to depend upon by investigation.

TODO

Does not (yet) support depending on:

• mining results from arbitrary autoplaced entities (Wood from trees)
• items created by a shortcut (that might be unlocked by a technology)
• Fish - a category all of their own
• loot from killing units
• water from an offshore pump