API design for egui widgets which take a `ref mut` as one of the arguments

[coderedart]

for egui widgets like ui:label("string"), its easy to just make a lua binding. lua will give us a String and we can use it for the ui.label() function. then, we just return Response struct to the lua api.

but some widgets like ui.text_edit() take a &mut String as an argument. unfortunately, lua strings, numbers, bools are immutable. so, we will never get a mutable reference from lua. so, we have two different designs for such mut ref functions.

Design 1

take a Table as argument for the function. tables can be mutable with setter functions for fields. we can simply ask user to provide us a table with the "value" field set to the editable data we need. we will just make a clone of the data, use mut ref value, and then set the changed value to that "value" field. we will return a Response as usual.

local my_text = {value: "some random string"}
ui:text_edit(my_text)

Design 2

take the value as argument, but return the changed value along the response as a tuple. this is much more intuitive.

local my_text = "some random string"
local my_text, response = ui:text_edit(my_text) 

ofcourse, we can always have both if necessary. i am leaning towards the second design for its simplicity.

[coderedart]

I will go with the first design of using a table. The second design will confuse new people as they may forget to use/store the return value properly. Both should be roughly equal in terms of performance.

Instead, we can provide some custom functions which deal with rust String and egui text_edit, as a performant alternative but with a more clunky interface.