LÖVE

zorg wrote:I think you want this (untested, sorry):

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o = 0
cmd = loadstring("o = sin(4)") -- returns a _function_
cmd() -- call that function
love.window.setTitle(o)

or even better:

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f = "sin(4)"
love.window.setTitle(loadstring("return " .. f))

though not if you want to set it every frame... that would probably be "slow as hell".

zorg wrote:I think you want this (untested, sorry):

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o = 0
cmd = loadstring("o = sin(4)") -- returns a _function_
cmd() -- call that function
love.window.setTitle(o)

or even better:

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f = "sin(4)"
love.window.setTitle(loadstring("return " .. f))

though not if you want to set it every frame... that would probably be "slow as hell".

f = "sin(4)"
love.window.setTitle(loadstring("return " .. f)())

• If there is an error in the code the user wrote, then it shouldn't spread to your code, or else your game will crash, to do this you can use pcall:

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  userinput = "math.sin(4); return 'a'"
  func = loadstring(userinput)
  ok,msg = pcall(func) --This call func, and returns true if there was no error or false if there was
  if ok then --The code ran fine
      if msg then 
          print(msg) --Prints "a"
      end
  else --Oops it crashed
      print(msg) --ERROR Bla bla bla
  end
  

• You dont want the user to execute dangerous code, for example if the user inputs:

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  love = nil

  Then your game wont act properly at all. To maintain the user away from your functions you can use setfenv:

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  env = {math = math, string = string}
  userinput = "love = {graphics = "a"}"
  func = loadstring(userinput)
  ok,msg = pcall(func)
  print(love.graphics)--table 0x....
  if ok then
      if msg then 
          print(env.love.graphics) --Prints "a"
      end
  else
      print(msg)
  end
  

  NOTE: If you want the user to use a function you have, then you should put it in the environment as I did above with math and string but this could be dangerous too, since you are just referencing a table, then if the user did this

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  math.floor = function () return 200 end

  math.floor wont do what you expect it to do, to allow the user to use math.floor while not allowing to change the behavior of YOURS math.floor you have to deep copy the math table

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  env = {math = deepcopy(math), string = deepcopy(string)}

  There are many deepcopy scripts here in the forum (Robin made an amazing one) so make a search and you'll find one

zorg wrote:Though you did make a minor typographical mistake: wrote "loadsting" instead of loadstring in one of your code blocks.

Positive07 wrote:-snip-