(LUA If Statements) Is It Just Me

[Captain Oveur]

or do LUA scripts start to fail when if statements have a lot of operands/parameters?

I tried to write a script that took several on/off inputs and a few number inputs to determine if my engine starters needed to be on or if the PID needed turned on. I even had the script to control the lever/throttle. There were statements that clearly should have failed (for example, the lack of a certain button input), yet the code within the if statement still executed. Every single logic output it was in charge of pressing was pressed all at once.

It's like the script ignored the actual if statement and just executed every single variable write it found in the entire script. This isn't a post-update thing either. This has been happening to me pretty much since I started playing. I have been using LUA scripts sparingly, relying almost completely on actual logic gates to perform complex tasks.

[GrumpyOldMan]

Most likely caused by your script rather than lua itself, an example would go a long way.

You can also use some sort of simplified state machine and use tables for states, if you have more complex conditions to check, helps with readability and convenience.

An engine controller would be a go-to example to make use of such a state machine, since an engine can only have a single state at any time (off, starting, idle, running, generator mode etc.) you'd set functions for each state in a table and go from there, instead of having tangled and intertwined nested if-statements.

[Captain Oveur]

I happen to still have the full script:

function onTick()
	rps = input.getNumber(1)
	fuel = input.getNumber(2)
	throt = input.getNumber(3)
	
	manMode = input.getBool(1)
	genOn = input.getBool(2)
	bat = input.getBool(3)
	
	starter = 0
	up = 0
	down = 0
	on = 0
	
	--If generator is supposed to be on
	if (manMode == 0 and bat == 1 and fuel > 0) or (manMode == 1 and genOn == 1) then
	on = 1
	end
	
	--Adjust throttle to starting position (if starting)
	if on == 1 and manMode == 0 and throt < .10 and rps < 2.5 then
	 up = 1
	elseif on == 1 and manMode == 0 and throt > .13 and rps < 2.5 then
	 down = 1
	end
	
	--Start engine if not running
	if on == 1 and rps < 2.5 then
	 starter = 1
	end
	
	--If running and automatic, send throttle to full
	if on == 1 and rps > 2.5 and manMode == 0 then
	 up = 1
	end
	
	--Stop the engine
	if on == 0 and rps > 0 then
	 down = 1
	end
	
	output.setBool(1, up)
	output.setBool(2, down)
	output.setBool(3, starter)
end

[GrumpyOldMan]

Just took a quick glance, seems you use output.setBool with numbers, which won't work.
First argument is the channel number, second one is required to be boolean (false/true), since lua does it differently than other languages and 0 is interpreted as true (or something among the lines).

[ShizNator]

Not having hands on and visual as to what is controlling/being controlled. But with what you gave I cleaned up your code and added some missing turn offs. And moved your variable checks out of onTick so they remain static and not deactivate every tic.

And as Grumpy stated on/offs must be true or false but you can use an alias like I show below.

T=true
F=false
starter = F
up = F
down = F
on = F

function onTick()
	rps = input.getNumber(1)
	fuel = input.getNumber(2)
	throt = input.getNumber(3)
	
	manMode = input.getBool(1)
	genOn = input.getBool(2)
	bat = input.getBool(3)
	
	--If generator is supposed to be on
	if not manMode and bat and fuel > 0 or manMode and genOn then on = T else on = F end
	
	--Adjust throttle to starting position (if starting)
	if on and not manMode and throt < .10 and rps < 2.5 then
	 up = T
	elseif on and not manMode and throt > .13 and rps < 2.5 then
	 down = T
	end
	
	--Start engine if not running
	if on and rps < 2.5 then
	 starter = T
	else starter = F end
	
	--If running and automatic, send throttle to full
	if on and rps > 2.5 and not manMode then
	 up = T
	end
	
	if throt >= 1 then up= F end
	
	--Stop the engine
	if not on and rps > 0 then
	 down = T
	end

	if throt <= 0 then down= F end
	
	output.setBool(1, up)
	output.setBool(2, down)
	output.setBool(3, starter)
end

[Captain Oveur]

Originally posted by GrumpyOldMan:

Just took a quick glance, seems you use output.setBool with numbers, which won't work.
First argument is the channel number, second one is required to be boolean (false/true), since lua does it differently than other languages and 0 is interpreted as true (or something among the lines).

Okay, but take the following example. It was the first iteration and produced a warning similar to "attempt to perform bitwise operation on a boolean value":

--If generator is supposed to be on
	if (~manMode and bat and fuel > 0) or (manMode and genOn) then
	on = 1
	end

It only threw that error for the "~manMode" part. That iteration of the script, I know I no longer have a copy of.

[EDIT]
Here's a gently modified version of the script I tried to make layed out in logic gate format. I'll go back over it eventually and replace a lot of it with boolean function blocks (I keep forgetting those exist).
https://steamcommunity.com/sharedfiles/filedetails/?id=3058432293

[Captain Oveur]

Originally posted by ShizNator:

And moved your variable checks out of onTick so they remain static and not deactivate every tic.

Wait, you can do that? I was under the impression the whole entire script was refreshed on each tick.

[edit]
Well, I'll be danged.

[GrumpyOldMan]

Originally posted by Captain Oveur:

Okay, but take the following example. It was the first iteration and produced a warning similar to "attempt to perform bitwise operation on a boolean value":

--If generator is supposed to be on
	if (~manMode and bat and fuel > 0) or (manMode and genOn) then
	on = 1
	end

It only threw that error for the "~manMode" part. That iteration of the script, I know I no longer have a copy of.

That error is to be expected, since you're using a bitwise operator on a boolean value, as the error message states. You can use "not" to check for false boolean:

--If generator is supposed to be on
	if (not manMode and bat and fuel > 0) or (manMode and genOn) then
	on = 1
	end

[Captain Oveur]

So '~' is an operator and not a conditional? I'll blame the internet for that one because I looked it up before using it.

[GrumpyOldMan]

SW is using lua 5.3, feel free to use this one for reference:
https://www.lua.org/manual/5.3/manual.html