Where did the generic class and method settings go?

DrScott

I’m running Objo Studio 26.7.1. I’m trying to write a generic Stack class, but the Advanced area in the class definition no longer seems to show the generic-defining fields that it used to show (on both macOS Tahoe and Golden Gate). Have these been moved somewhere else?

Garry

There hasn’t been a language change here: generic classes and methods are still supported.

For generic methods, select the method in the member sidebar, expand the method editor’s Advanced section, and use Generics. Enter only the contents, for example T or T As Comparable; Studio emits Function Name(Of T)....

For a generic class such as Class Stack(Of T), I need a little more detail about what workflow you’re using. Are you trying to add (Of T) through the class inspector, or are you editing the class declaration directly? If you can paste the minimal Stack declaration/members you’re trying to create, or list the exact Studio steps, I can tell whether there’s an existing way to do it or whether we’ve got a Studio UI gap around class/interface generic declarations.

DrScott

Hi Gary,

I just found the method Generic definition in the Advanced section (for some neon, I thought it was gone). But I'm still unsure how to define a generic class. I tried adding (f T) to the class name, but that wasn't accepted. I couldn't see any other ay to add it except perhaps hand-editing the VCS file.

Maybe classes also need an Advanced section with generic definition in it.

bgrommes

DrScott You just need to put T in there, not Of T.

DrScott

Adding just (T) to the class name (i.e., Stack(T)) is a problem. Once the first parenthesis is typed, the Stack class becomes inaccessible. All that shows up in the class description is "Stack(", with the text field to enter the class name gone.

bgrommes

IIRC the class name is still just Stack.
The (Of T) will come from the advanced generics text box, where you put just the T.

DrScott

For classes, the Advanced section doesn’t have any generics text field, at least not any that I can find. All it has is Deprecated and Message.

bgrommes

DrScott D'oh! Sorry. I was thinking of methods, not classes. I'll defer to Garry on that issue.

DrScott

Hi Garry,

Sorry I didn't respond sooner -- another bad migraine day and I forgot. The Stack class is very simple. Here's its properties and methods:

class Stack
property items as Array(Of T)

Method Clear()
Method Pop() As T
Method Push(item As T)
end class

Garry

Thanks Scott. I think there was a real Studio UI gap.

Generic classes and interfaces were still supported by the language/compiler, but Studio 26.7.1 did not expose generic type parameters in the class/interface inspector. Generic methods already had an Advanced > Generics field, but classes only showed Deprecated and Message, so there was no clean UI path for creating something like:

Class Stack(Of T)

I’ve fixed this for the next release: https://feedback.objo.dev/bug/684

In the next release, normal class and interface inspectors will have a new Advanced > Generics field, matching the existing generic method workflow. The class name should remain just:

Stack

and the Generics field should contain only:

or, for constrained type parameters:

T As Comparable

Studio will then emit the declaration as:

Class Stack(Of T)

So your Stack example should be achievable.

I also fixed the confusing Name-field behaviour. If you type Stack(Of T) into the Name field, Studio will now split that into Name = Stack and Generics = T. If you type Stack(T), Studio will also normalise that to the real Objo syntax and emit Class Stack(Of T). Partial input such as Stack( should no longer leave the inspector in that broken Stack( state.

Existing generic class/interface declarations are also preserved and loaded back into the inspector. So if a file already contains Class Stack(Of T), selecting the class will show Stack in the Name field and T in Advanced > Generics. Rename, duplicate, superclass, interface, scope, and deprecation edits now preserve the generic declaration too.

Generic methods are unchanged: for a method, continue to use the method editor’s Advanced > Generics field and enter only the contents, e.g. T or T As Comparable.

bgrommes

Garry This flexibility of inputting the generic spec wherever it makes sense and the environment just figuring it out, is IMO a Good Thing and will do its part to reduce the amount of support questions you will get over time (of the "how do I enter this" variety).

If I'm reading you correctly if you enter e.g. Stack(Of T) in the name field, it will change to Stack and put T in the generics field, right then and there. I would suggest also maybe auto-expanding the Advanced area just to make it more obvious what is going on. Because here you might have someone say, "I entered Stack(Of T) and Studio keeps changing it back to Stack, this is a bug" without realizing what happened. It might also be wise in the long run to put up a tool tip explaining this was done for the user.

Another thought that occurs to me is that when you collapse a method or class definition, the actual declaration will show at the top, above the code editor. It might make sense to put this somewhere in front of the user even when the method definition isn't collapsed, so they can see it evolve in real time and be reassured it is what they intend. Perhaps that could be a configurable thing, on by default, and could be turned off by the user once they are more accustomed to how things work. Even if you elect not to do this I'd suggest that the collapsed display of the class or method definition include things like Sub/Function, Shared, Override, etc. in addition to the bare method signature and return type, as I think these things are helpful both to the user generally and to put in front of them most of what they would see in a text editor along with the actual code.

Garry

I tried the exact workflow and found a related inspector bug: Studio was already splitting Stack(Of T) correctly by putting T into Generics, but the active Name field could keep showing Stack(Of T) until you selected away and came back. That made the UI look half-normalised.

I’ve fixed that for the next release.

Now if you enter Stack(Of T) or Stack(T) in the Name field, Studio immediately changes Name to Stack, expands Advanced, shows T in Generics, and emits:

Class Stack(Of T)

That should make the transformation visible instead of looking like Studio either ignored or lost part of the name.

DrScott

Thank you, Garry.