Writing function to check state's machine current state [Lua/Love2d] - lua

Question

I'm learning game development with LÖVE2D and Lua and lately I've been using a state machine class. I haven't coded the class myself, but I've went through the code and I think I pretty much got it, besides this one problem.
The thing is, I'm trying to prompt the class for its current state, just so I can use it inside an if, but no matter what, I cannot get it right.
Here's the relevant code of the class:
StateMachine = Class{}
function StateMachine:init(states)
self.empty = {
render = function() end,
update = function() end,
enter = function() end,
exit = function() end
}
self.states = states or {} -- [name] -> [function that returns states]
self.current = self.empty
end
function StateMachine:change(stateName, enterParams)
assert(self.states[stateName]) -- state must exist!
self.current:exit()
self.current = self.states[stateName]()
self.current:enter(enterParams)
end
What I'm basically trying to do is:
function StateMachine:is(stateName)
if self.current == self.states[stateName] then
-- this never executes
return true
end
return false
end
I've tried changing self.states[stateName] to other things to test it out and also tried printing stuff to the console to see why the comparison is never true. It seems self.current returns a pointer to a table and thus never matches whatever is on the other side of the comparison operator.
Thanks for your help!

Answer 1

self.current is set to the return value of self.states[stateName] in StateMachine:change
function StateMachine:change(stateName, enterParams)
...
self.current = self.states[stateName]() -- note the () indicating the call
This means, unless the return value is self, self.current will not be equal to the function or object self.states[stateName] that it is compared to in StateMachine:is
function StateMachine:is(stateName)
if self.current == self.states[stateName] then -- here we are comparing the function to the return value
I would suggest expanding your state object to have a :getName function that would return the stateName or to store the name in your StateMachine under a key such as currentStateName.

Answer 2

I had the exact same question & I'd like to add--perhaps some of the comments explain this in language I just didn't understand :D--but in the getCurrentState function I created I had to do this:
function StateMachine:getCurrentState()
variable = self.currentStateName
return variable
where ofc variable is just some placeholder. but I had to grab the reference that self.currentStateName was pointing to, otherwise the comparison always failed.