Can you help me see what's wrong with it?

[sdgmlj]

Code: Select all

local g = game.recipe_prototypes[item_name]
	for _,e in pairs(game.entity_prototypes) do
		for _,c in pairs(e.crafting_categories) do
			if c == g.category then
			。。。。。。。。
			end
		end
	end

I want to find out all the production machines of this formula, but it always reports errors. Where is the error? Thank you

[Pi-C]

Code: Select all

local g = game.recipe_prototypes[item_name]
	for _,e in pairs(game.entity_prototypes) do
		for _,c in pairs(e.crafting_categories) do
			if c == g.category then
			。。。。。。。。
			end
		end
	end

I want to find out all the production machines of this formula, but it always reports errors. Where is the error? Thank you

crafting_categories :: dictionary[string → boolean] [Read]

So changing the inner loop like this should work:

Code: Select all

-- for _,c in pairs(e.crafting_categories) do
for c, _ in pairs(e.crafting_categories) do

By the way, this is something you could easily have found out yourself by adding some debugging output. I usually always print out the current values of loop variables when I add a new function, just to be sure that the tables I use really contain what I need:

Code: Select all

local function show(msg, var)
  log(string.format("%s: %s", msg, serpent.block(var)))
end

local g = game.recipe_prototypes[item_name]
show("g", g)

for _,e in pairs(game.entity_prototypes) do
  show(_, e)

  for _,c in pairs(e.crafting_categories) do
    show(_, c)
    if c == g.category then
	。。。。。。。。
    end
  end
end

[sdgmlj]

First of all, thank you very much for your help. I will change the content to:

for c,_ in pairs(e.crafting_categories) do

It still reports an error with the content "bad argument \1 of 2 to'pairs'(table expected, got Nil)"

[sdgmlj]

Code: Select all

local g = game.recipe_prototypes[item_name]
	for _,e in pairs(game.entity_prototypes) do
		for _,c in pairs(e.crafting_categories) do
			if c == g.category then
			。。。。。。。。
			end
		end
	end

I want to find out all the production machines of this formula, but it always reports errors. Where is the error? Thank you

crafting_categories :: dictionary[string → boolean] [Read]

So changing the inner loop like this should work:

Code: Select all

-- for _,c in pairs(e.crafting_categories) do
for c, _ in pairs(e.crafting_categories) do

First of all, thank you very much for your help. I will change the content to:

for c,_ in pairs(e.crafting_categories) do

It still reports an error with the content "bad argument \1 of 2 to'pairs'(table expected, got Nil)"

[jodokus31]

First of all, thank you very much for your help. I will change the content to:

for c,_ in pairs(e.crafting_categories) do

It still reports an error with the content "bad argument \1 of 2 to'pairs'(table expected, got Nil)"

Then you have to check that e.crafting_categories is not nil

Code: Select all

if e.crafting_categories then
  for c,_ in pairs(e.crafting_categories) do
    ..
  end
end

[sdgmlj]

First of all, thank you very much for your help. I will change the content to:

for c,_ in pairs(e.crafting_categories) do

It still reports an error with the content "bad argument \1 of 2 to'pairs'(table expected, got Nil)"

Then you have to check that e.crafting_categories is not nil

Code: Select all

if e.crafting_categories then
  for c,_ in pairs(e.crafting_categories) do
    ..
  end
end

OK, that's the reason. My problem has been solved. Thank you

[Pi-C]

Then you have to check that e.crafting_categories is not nil

Code: Select all

if e.crafting_categories then
  for c,_ in pairs(e.crafting_categories) do
    ..
  end
end

Even simpler:

Code: Select all

 
  for c,_ in pairs(e.crafting_categories or {}) do
    ..
  end

[jodokus31]

Then you have to check that e.crafting_categories is not nil

Code: Select all

if e.crafting_categories then
  for c,_ in pairs(e.crafting_categories) do
    ..
  end
end

Even simpler:

Code: Select all

 
  for c,_ in pairs(e.crafting_categories or {}) do
    ..
  end

Good point.