[Solved] Modifying underground belts

[ethical_apple]

Hello, I'm trying to create a mod that has a higher maximum length for new underground belts. However, I'm encountering an issue with the internal and prototype name of "underground-belt" which is not recognized properly due to having the hyphen.

A makeshift solution was:

Code: Select all

data.raw["underground-belt"]["underground-belt"].max_distance = 64

however this directly modifies existing belts, while I want to make new ones altogether.

When trying

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local underground-belt = table.deepcopy(data.raw.underground-belt["underground-belt"])

the hyphen messes with it and it can't be read.

Lua claims there's an unexpected symbol, which is obviously the hyphen, so how can I fix this? Sorry if it's a no-brainer, I'm still new to Lua in general.

[eduran]

Square brackets are the default way to access table elements by key. The dot syntax only works if the key is string consisting only of alphanumeric characters and underscores. The first character has to be a letter or underscore, not a number. The same is true for variable names.

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local t = {}
t[1]  = 1
t["hi"] = 2
t["a-b"] = 3

-- this works:
game.print(t.hi)  --> 2

-- this does not work:
game.print(t.1) 
game.print(t.a-b) 
local underground-belt = 1  -- lua interprets the hyphen as minus and does not know what to do with this statement

-- instead use
game.print(t[1])  --> 1
game.print(t["a-b"]) -->3
local underground_belt 

In your case, lua reads the hyphen as a minus. What you are looking for is

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local name_without_special_characters = table.deepcopy(data.raw["underground-belt"]["underground-belt"])

[darkfrei]

Just use "local underground_belt" instead of "local underground-belt".

[ethical_apple]

Square brackets are the default way to access table elements by key. The dot syntax only works if the key is string consisting only of alphanumeric characters and underscores. The first character has to be a letter or underscore, not a number. The same is true for variable names.

Code: Select all

local t = {}
t[1]  = 1
t["hi"] = 2
t["a-b"] = 3

-- this works:
game.print(t.hi)  --> 2

-- this does not work:
game.print(t.1) 
game.print(t.a-b) 
local underground-belt = 1  -- lua interprets the hyphen as minus and does not know what to do with this statement

-- instead use
game.print(t[1])  --> 1
game.print(t["a-b"]) -->3
local underground_belt 

In your case, lua reads the hyphen as a minus. What you are looking for is

Code: Select all

local name_without_special_characters = table.deepcopy(data.raw["underground-belt"]["underground-belt"])

Thank you very much. Your solution works and you taught me something along the away.