GDScript function arguments with default values shouldnt have to be the last argument(s)

[balloonpopper]

Describe the project you are working on

Tycoon game

Describe the problem or limitation you are having in your project

If I have a function where I specify a default value for an argument, all following arguments require a default value. I have a convention for my functions and this limitation means I need to reorder the parameters for all my functions to fit ones where I want to provide a default value.

Currently this is allowed
func MyFunc(a:int, b:int=20)

But this is not allowed
func MyFunc(a:int=50, b:int)
(Error message : "Parser Error: Default parameter expected.")

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Any function argument with a default value would be able to be followed by one without a default value.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

This code in the editor
func MyFunc(a:int=50, b:int)

Will not cause the error : "Parser Error: Default parameter expected.")

If this enhancement will not be used often, can it be worked around with a few lines of script?

It can be worked around by coding your functions differently, but the current limitation is an arbitrary limitation as far as I can see, and the behaviour (and current error message) aren't intuitive.

Is there a reason why this should be core and not an add-on in the asset library?

Its a core part of GDScript

[Calinou]

I don't see how this is technically feasible, as this means the order of arguments would have to vary depending on the number of arguments specified when calling the function. I think allowing this kind of syntactic freedom where the argument order can differ between the definition and call is asking for trouble. Also, I haven't seen any other widespread programming language allow something like that.

[timothyqiu]

For a function like:

func foo(a=1, b, c=2, d)

what should foo(1, 2, 3) result in?

[balloonpopper]

Oops. I hadn't thought it through properly as I wasn't picturing the scenario you mentioned. Thinking through it further, I agree, you'd need to leave the parameter empty if you wanted to use one with a default value - so you couldd end up with a call like
foo(,2,,3)
to preserve the correct number of parameters, and that's not a good solution.

Lets amend my proposal to "Lets document that you need every parameter after one with a default value to also have a default value"

[AaronRecord]

I think what you really want is #1571 and #902

[YuriSizov]

This is also closely related to #1117, which was closed per GDScript maintainer's comment.