First Draft: Static Single Assignment

[Peter C]

On Tuesday, 18 November 2025 at 10:24:17 UTC, Jonathan M Davis 
wrote:
>
> ...
> 2. Adding _any_ keyword is a breaking change, so the odds of it 
> happening are pretty low in general. If there's a strong case 
> for it with a particular feature, then it might happen, but if 
> an existing keyword can reasonably be used instead (or some 
> other syntax which wouldn't be a breaking change), that's 
> almost certainly what's going to happen when adding a feature. 
> ...
> - Jonathan M Davis

Again, a *contextual* keyword like 'fixed' would solve the issue 
of compatability.

Why do I think something other than 'final' is needed?

Because of this 'real world' example:

It's from: 
https://github.com/ProjectDVN/dvn/blob/main/source/dvn/application.d

i.e. adding yet another overloaded meaning to 'final' would be 
conceptually confusing at the very least. I would call it out 
further, as being poor language design!

public final class Application
{
   private:
   FontCollection _fonts;
   bool _running;
   Tid _uiTid;
   int _fps;
   Color _defaultWindowColor;
   Window[] _windows;
   bool _allowWASDMovement;
   size_t _concurrencyLevel;
   size_t _messageLevel;
   bool _isDebugMode;

   public:
   final:
   this(int defaultFps = 60)
   {
     this(getColorByName("white"), defaultFps);
   }

   this(Color defaultWindowColor,int defaultFps = 60)
   {
     if (defaultFps <= 0 || defaultFps > 240)
     {
       throw new ApplicationException("Invalid default fps.");
     }

     _defaultWindowColor = defaultWindowColor;
     _fonts = new FontCollection;
     _fps = defaultFps;
     _windows = [];
     _concurrencyLevel = 4;
     _messageLevel = 42;

     if (!_app)
     {
       _app = this;
     }
   }