GMS2 f()

f() is a single script dependency that gives you virtual private functions within objects in GameMaker Studio 2.

GameMaker Studio 2 has a limitation in which all user scripts ("functions") are in the global space, which can lead to your project becoming very messy. f() attempts to solve this problem by wrapping User Events (See: Other -> User Events) in an intelligent way and implementing a return system from these events.

This allows you to implement custom functions within the scope of a single object, which keeps the Scripts section of your project clean, and constrains one-off functionality to its owner.

TL:DR

1. Open the included project
2. Look at object0 -> Create Event
3. Run project and press keys 0, 1, 2, 3, spacebar
4. Monitor the Output Console

How do I use it?

In your object, add the following to your Create Event.

//f() function declarations
functions = [
    "my_custom_function", // index 0 -> user event 0
    "my_other_function", // index 1 -> user event 1
];

You will declare your function names in User Event numerical order in the "functions" array. That is to say, the function that correlates to User Event 0 will be first, the function that correlates to User Event 1 will be second, etc.

In your code, you may then call your function and its arguments in one of three ways:

METHOD 1: f("my_custom_function('a string argument',1,2.532,true)");

METHOD 2: f("my_custom_function",["a string argument",1,2.532,true]);

METHOD 3: f("my_custom_function","a string argument",1,2.532,true);

You will then write your custom function code in the respective User Event. The only caveats are that your return will have to be placed into a variable...

example User Event 0:

WRONG:
    return my_variable;
RIGHT:
    _return = my_variable;

and your arguments will be prepended with an underscore... example User Event 0:

WRONG:
    var my_variable = argument0 + argument1;
RIGHT:
    var my_variable = _argument0 + _argument1;

From your User Event you can also see how many arguments to expect with

_argument_count

and you can access more than 16 arguments by using the array

_argument[0 ... max_num]

How does it work?

Basically just parsing strings and using custom variables local to the object. Check out the code I have heavily commented it.

What are the limitations?

GameMaker Studio 2 only allows 16 User Events per object, so you cannot exceed 16 custom functions using f().