Refining this: - inline classes are inlinable (duh) - reference classes, interfaces, and nullable-projections of zero-default inline classes are not inlinable
(We later use these to say: Instantiation of generics with non-inlinable types are erased.) That seems not terrible, except for the “nullable projection of zero-default inline classes” part, which is both a mouthful and has “inline” in it. Perhaps calling these something like “null-adjoined types” (to reflect the fact that we’re cramming a null into a type whose value set doesn’t naturally contain null) makes that slightly better. So: - inline classes are inlinable - reference classes, interfaces, and null-adjoined types are not inlinable > On Apr 8, 2019, at 3:06 PM, Brian Goetz <brian.go...@oracle.com> wrote: > > A related issue is that we want a word for describing which types are > routinely flattened in layouts, and specialized in generics (the criteria are > the same). Currently: > > - References and nullable projections of values (V?) are erased and not > flattened > - Values (zero-default and null-default) are specializable and flattenable > > (This thread is for terminology; if you have questions about the above > claims, make a new thread, or better, wait for the more detailed writeup > explaining why this is.) > > We need words for these two things too. > >> On Apr 8, 2019, at 2:58 PM, Brian Goetz <brian.go...@oracle.com >> <mailto:brian.go...@oracle.com>> wrote: >> >> Yes, that’s a promising direction. And this is surely the motivation why >> the C# folks picked “struct”; they wanted to carry the connotation that this >> is a structure that is inlined. Problem is, the word “struct” is already so >> heavily polluted by what it means in C. So perhaps something like: >> >> inline class V { … } >> >> This says than a V can be inlined into things that contain a V — other >> classes and arrays. It also kind of suggests that this thing has no >> intrinsic identity. >> >> A possible downside of this choice is that one might mistake it for meaning >> “its methods are inlined”. Which is actually a little true, in that the >> methods are implicitly static and therefore more amenable to dynamic >> inlining. So that might actually be OK. >> >> Others? >> >>> On Apr 8, 2019, at 2:25 PM, Kevin Bourrillion <kev...@google.com >>> <mailto:kev...@google.com>> wrote: >>> >>> I'd suggest the name should in some way allude to the inline/compact/flat >>> memory layout, because that is the distinguishing feature of these new >>> things compared to anything else you can do in Java. And it is what people >>> should be thinking about as they decide whether a new class should use this. >>> >>> >>> On Mon, Apr 8, 2019 at 10:02 AM Brian Goetz <brian.go...@oracle.com >>> <mailto:brian.go...@oracle.com>> wrote: >>> The slide deck contains a list of terminology. I’d like to posit that the >>> most confusion-reducing thing we could do is come up with another word for >>> value types/classes/instances, since the word “value” is already used to >>> describe primitives and references themselves. This is a good time to see >>> if there are better names available. >>> >>> So for this thread only, we’re turning on the syntax light to discuss what >>> might be a better name for the abstraction currently known as “value >>> classes”. >>> >>> >>> >>> > On Mar 29, 2019, at 12:08 PM, John Rose <john.r.r...@oracle.com >>> > <mailto:john.r.r...@oracle.com>> wrote: >>> > >>> > This week I gave some presentations of my current thinking >>> > about specializations to people (from Oracle and IBM) gathered >>> > in Burlington. Here it is FTR. If you read it you will find lots >>> > of questions, as well as requirements and tentative answers. >>> > >>> > http://cr.openjdk.java.net/~jrose/pres/201903-TemplateDesign.pdf >>> > <http://cr.openjdk.java.net/~jrose/pres/201903-TemplateDesign.pdf> >>> > >>> > This is a checkpoint. I have more tentative answers on the >>> > drawing board that didn't fit into the slide deck. Stay tuned. >>> > >>> > — John >>> >>> >>> >>> -- >>> Kevin Bourrillion | Java Librarian | Google, Inc. | kev...@google.com >>> <mailto:kev...@google.com> >
