Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

> On Nov 22, 2017, at 6:48 AM, Brian Goetz wrote: > > What's the L-world story for array subtyping? For any R-type, R[] <: > Object[]. If everything is an L type and everything is <: Object, are arrays > of Q-types/primitives also subtypes of Object[]? > > We didn't

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

> De: "John Rose" > À: "Brian Goetz" > Cc: "valhalla-spec-experts" > Envoyé: Mercredi 22 Novembre 2017 19:48:18 > Objet: Re: abandon all U-types, welcome to L-world (or, what I learned in > Burlington) > On

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

On Nov 22, 2017, at 5:48 AM, Brian Goetz wrote: > > What's the L-world story for array subtyping? For any R-type, R[] <: > Object[]. If everything is an L type and everything is <: Object, are arrays > of Q-types/primitives also subtypes of Object[]? > > We didn't

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

What's the L-world story for array subtyping?  For any R-type, R[] <: Object[].  If everything is an L type and everything is <: Object, are arrays of Q-types/primitives also subtypes of Object[]? We didn't have a story for this in QU-world either, but at least in QU-world it was believable

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

On Nov 19, 2017, at 3:33 PM, fo...@univ-mlv.fr wrote: > > but you need a way disambiguate a reference type from a value type at runtime > in the interpreter. > You also nedd to teach JITs to propagate L vs which Q info on local variables > for generics specialization (and it works even if the

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

- Mail original - > De: "John Rose" > À: "Remi Forax" > Cc: "valhalla-spec-experts" > Envoyé: Lundi 20 Novembre 2017 00:06:20 > Objet: Re: abandon all U-types, welcome to L-world (or, what I learned in >

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

On Nov 19, 2017, at 2:47 PM, Remi Forax wrote: > > The claim is that Object is used more as the root of any types like in > collections than as the root of all references like in System.out.println(). Object and interfaces play the role of top types. One view is that we are

Re: abandon all U-types, welcome to L-world (or, what I learned in Burlington)

To summarize for myself, we already know that we only need only one U, java.lang.__Value, let try to make it java.lang.Object (with no boxing). The claim is that Object is used more as the root of any types like in collections than as the root of all references like in System.out.println().

abandon all U-types, welcome to L-world (or, what I learned in Burlington)

We just had a 50-hour week of face-to-face meetings by the Valhalla VM team. We learned a lot and surprised ourselves by coming to a consensus that a promising design for value types uses mainly the same legacy L-type descriptors, makes relatively little use of Q-type descriptors, and does not