local parseCommand = function(str)
    --[[
    * Lua uses the \ for escaping characters - not the pattern part though, that
      uses the % - so every character that is after a % is an escape sequence.
    * Here is a common one: %s - this is a character set - contains all whitespace
      characters, including \t, space itself, etc.
    * + is suffix. It means that we have more than 0 of the character
      (or character set, like %s) which it follows
    * ( and ) enclose a capture - .gsub returns the content of every capture, or if
      there is no capture at all, the whole pattern
    * . means ANY character
    * as you can see, we captured a sequence of characters with "(.+)" - the pattern
      looks for SOME whitespaces at the beginning, then for some characters of ANY kind,
      then whitespaces again - we caprute the ANY character part, and that's what .gsub
      returns - yay, we have the full command without spaces on its ends
    ]]
    str = str:gsub("%s+(.+)%s+")
    local words = {}
    --[[
    * .gmatch is an iterator - it creates a table which contains all occurences of the
      pattern in the string - then it returns a function which - if used properly in a
      for loop, iterates through that table
    * ^ means NOT, so [^%s] is a pattern which contains no whitespaces, but does contain
      something (hence the +) - result: we have a words table filled with the words
    ]]
    for word in str:gmatch("[^%s]+") do table.insert(words, word) end
    -- now words[1] contains the command itself
    if words[1] then
        -- you can go on from now I think
        if words[1] == "open" and words[3] == "door" then

        elseif words[1] == "close" and words[3] == "door" then

        elseif words[1] == "turn" and words[3] == "lights" then

        elseif words[1] == "add" then

        elseif words[1] == "remove" then

        else
            -- prints an error message about words[1] not being a real command
        end
    else
        -- str was empty
        -- you can remove this branch of course
    end
end