Factorio Forums

bobingabout wrote:I think some of the most confusing ones for me are those like this:
viewtopic.php?f=51&t=33539
Not because it's a confusing error in itself, it quite clearly states that an item with that name doesn't exist. The confusion is well... what mod is causing this?

in this specific case, it was Angel's mod for my mods that wanted an item from one of the mods that wasn't installed. and unlike my mods, it doesn't check if it exists before trying to access it. But when you get a bug report like that, it does make it a little difficult to diagnose the issue.

From my understanding, when the mod name, and even file line isn't given, it's because the line itself doesn't cause an error, so the problem goes un-noticed until everything is being parsed at the end of the stage.
Perhaps something that could help is to list a specific recipe that referenced the item, and what mod/mods add/edit said recipe, similar to the list in game that might say "bobores->bobplates->5dim->angelores" when you hover over a recipe that was added in my mod, then edited several times. At least it narrows down the field of what we need to look at.

aubergine18 wrote:I was stumped by a stack overflow error recently, turned out that I'd missed a `pairs()` in a `for` loop.

Code: Select all

for k,v in foobar do
  -- my code here caused a stack overflow
end

It's one of those blunders where you can end up starting at the screen for hours without spotting the obvious mistake. If possible, when a stack overflow occurs, could the error message state "Did you forget to use pairs() or ipairs() in a for loop?"

aubergine18 wrote:Just run in to the node error again:

Code: Select all

Error while loading tile prototype "wood-floor" (tile): No such node (side)

Would be better if it said something like:

Code: Select all

Prototype error in "wood-floor" (tile): Mandatory "side" property not found.

Note: Even with that improved error message, I'd still struggle in the absence of documentation about prototypes and their properties. For example, it would take some time to track down that `side` is a property of the `variants` property (in this case I already know that to be the case as I know that tiles have a `side` property in that locaiton).

aubergine18 wrote:Just ran in to this error

Code: Select all

   1.283 Error Util.cpp:57: Failed to load mod "Epoch 0.0.1"
__Epoch__/data.lua:19: ...io/factorio.app/Contents/data/core/lualib/dataloader.lua:16:
Missing name or type in the following prototype definition {} --[[table: 0x0000000116368890]]

Seems it was caused by a copy/paste blunder in one of my protos:

Code: Select all

data:extend {
  {
  }
}

Mooncat wrote:I don't know if anyone has encountered this before:

Code: Select all

Failed to load mod "my-mod 0.1.0" __mod__/data.lua:1: ...io/factorio.app/Contents/data/core/lualib/dataloader.lua:11: Invalid prototype array nil

Took me 30 minutes to figure out I shouldn't try to manually type the prototype files, because I typed

Code: Select all

data.extend(

but not

Code: Select all

data:extend(

I should have copied it from the existing files instead.
Maybe a hint about this when invalid prototype array nil error occurs?

Also, I agree with aubergine18, we really need an updated document about prototypes. Currently, making prototypes is a puzzle game. Everyone knows a little bit about it. We gather information from the others to create a complete mod. It is fun, but also time consuming. A document will be much helpful.

mexmer wrote:well, main issue with prototypes is, that we don't know which attributes are mandatory, and which are optional.
you might assume, that "all" attributes you find on vanilla item definition are mandatory, but that's not always true, you need to find "right" prototype you can copy and reuse (i'm writing prototypes, but i have not found any single real prototype in item definitions, so i take "base vanilla items" as prototypes, although that is not correct)

also there is that difference between "item definition" prototype, and "parser" prototype

    action =
    {
      type = "direct",
      action_delivery =
      {
        type = "instant",
        source_effects =
        {
          {
            type = "nested-result",
            affects_target = true,
            action =
            {
              type = "area",
              perimeter = 6,
              collision_mask = { "player-layer" },
              action_delivery =
              {
                type = "instant",
                target_effects =
                {
                  type = "damage",
                  damage = { amount = 40, type = "explosion"}
                }
              }
            },
          },
          {
            type = "create-entity",
            entity_name = "explosion"
          },
          {
            type = "damage",
            damage = { amount = 1000, type = "explosion"}
          }
        }
      }
    },

Mooncat wrote:

mexmer wrote:well, main issue with prototypes is, that we don't know which attributes are mandatory, and which are optional.
you might assume, that "all" attributes you find on vanilla item definition are mandatory, but that's not always true, you need to find "right" prototype you can copy and reuse (i'm writing prototypes, but i have not found any single real prototype in item definitions, so i take "base vanilla items" as prototypes, although that is not correct)

also there is that difference between "item definition" prototype, and "parser" prototype

That's why we need the devs to make the doc. Only they know all the possibilities of prototypes.

To me, item prototype is not a big issue. There are not too many possible attributes.
The main issue is entity prototype. There are many different entity types, and each entity type has different set of attributes.
And not only entities, but attributes can also have different types. Here is part of the land-mine entity:

Code: Select all

    action =
    {
      type = "direct",
      action_delivery =
      {
        type = "instant",
        source_effects =
        {
          {
            type = "nested-result",
            affects_target = true,
            action =
            {
              type = "area",
              perimeter = 6,
              collision_mask = { "player-layer" },
              action_delivery =
              {
                type = "instant",
                target_effects =
                {
                  type = "damage",
                  damage = { amount = 40, type = "explosion"}
                }
              }
            },
          },
          {
            type = "create-entity",
            entity_name = "explosion"
          },
          {
            type = "damage",
            damage = { amount = 1000, type = "explosion"}
          }
        }
      }
    },

My mind was nearly blown when I first saw this. So many different "type"s. Yet, there may be more somewhere in the prototype files, waiting to be explored by us.
With the doc, I expect it can tell us what are the possible contents inside "action", "action_delivery", "source_effects", and what are the possible values of those "type"s.
I know it will take time to write the doc. I just hope we will have it in the future.

Edit: and please prepare the doc when you, the devs, are creating new prototype (e.g. entity) types.

mexmer wrote:for item/entity prototype we don't need exactly doc, validation schema should be enough.
i suspect they are using something like this http://json-schema.org/ otherwise writing validator for any and every item type will be tedious task.