Feedback on LazyConstants (formerly StableValues)

[Maurizio Cimadamore]

On 24/09/2025 11:38, Per-Ake Minborg wrote:
> I think the other examples you show (albeit I didn't fully get how 
> they were supposed to work) would have issues regardless of whether 
> there were language or library support for lazy computation

I'd like to amplify this point a little.

Your example shows the use of a singleton -- an object that is 
constructed once, then stashed in a static final field.

However, the construction of the singleton (getInstance method) depends 
on a parameter.

This means that, effectively, getInstance will capture whatever 
parameter value was passed the first time it was constructed.

Now, there might be use cases for this, but such a use case would also 
not be supported if using Kotlin's lazy, Scala's lazy val, or our 
LazyConstant API (all of them are equivalent from an expressiveness 
point of view).

So, your claim that

> this may indicate that a keyword or annotation-based solution could be 
> a better fit.
Feels a bit off -- either the example you provided is not what you 
really had in mind, or, when you say _keyword_ you mean something other 
than a lazy-like keyword (but as Per explained, while there are some 
more obscure keywords in other languages that might provide more 
flexibility, the semantics associated with such keywords feels a bit 
ad-hoc, and surely not something we would like to permanently bolt onto 
the language).

Cheers
Maurizio