Linked Lists in Lua

Alright, I'm trying to create a linked list in Lua, but I'm having a slight issue. I know how to do it, but not why it works.

Can someone explain the following line of code to me?

list = {next = list, value = v}

To create a linked list I would do something like the following.

for i = 1,5 do
    local v = io.read()
    list = {next = list, value = v}
end

Then to show it I would go.

do
   local l = list
   while l do
       print(l.value)
       l = list.next
   end
end

One again, all of it makes sense except the following.

list = {next = list, value = v}

If anyone here knows how this works and can explain it that would be great.

the second "list" is evaluated to the current value of "list", then "list" is rebound with = to the table containing the old value.

It's not so different from i = i + 1

>>2
Okay, so because the right side of the assignment is evaluated first the old table address is saved inside the table and a new object is created for the variable being assigned. If it's the first table then next is given a nil value.

Is that right? I think I get it now.

>>3
right.

it just looks a little zaney because it uses list before it is initialized (purposefully)

and it might be a bit confusing to a C programmer to have a heap object like a table just be thrown somewhere else and then overwritten, when it sort of looks like it's on the stack.

you should probably forget the heap/stack distinction. Lua doesn't even use it and has a register-based VM.

>>4
Thanks for the tips, but I'm not really a C programmer, at least not until I finish this book, all the exercises in it, and then apply the knowledge.

...and yet I still needed help for this.

Thanks!

This implementation of a linkedlist works but I don't like it.

Alright, I'm trying to create a linked list in Lisp, but I'm having a slight issue. I know how to do it, but not why it works.

(cons 'car '(cudder))

If anyone here knows how this works and can explain it that would be great.