4 ms·

But what I don’t get reading the original article is that they present how to insert struct in an object oriented language as an intractable problem, whereas a

by cm2187 4mo ago

But what I don’t get reading the original article is that they present how to insert struct in an object oriented language as an intractable problem, whereas a good implementation with .net (as far as I can tell) has been out there for nearly 30 years. And C# was shameless about stealing from other languages.

pjmlp 4mo ago
The problem is how to do it without breaking ABI, 30 years of Maven Central is very relevant, Java isn't doing a Python over value types.
- cm2187 4mo ago
  But if you define a new type, how is that breaking backward compatibility?
  - pjmlp 4mo ago
    Because that is missing the point. All the types that are value types in semantics, e.g. Optional, should be proper value types on Valhalla. Additionally, they should be compatible with existing code that expects them as parameters, fields,.... without being recompiled from source. If it is a complete new type without backwards compatibility, no one is going to adopt it, other than a few niche cases.
  - gf000 4mo ago
    Well, my old code can have a List<Object>, and I can pass my new type into it and have it do some operations. Let alone with reflection - so backwards compatibility is more complex than that. As for structs, Java avoids e.g. tearing issues with making them immutable, while it is easy to optimize it to local modification under the hood.
Someone 4mo ago
> how to insert struct in an object oriented language as an intractable problem, whereas a good implementation with .net (as far as I can tell) has been out there for nearly 30 years. And C# was shameless about stealing from other languages. I think (but may be wrong) their concerns are about the insert part. C# always had structs, Java wants to add them in a backward-compatible way. They want, for example, existing generic container classes pulled in from a .jar (i.e. already compiled) to support Java value types.
Zardoz84 4mo ago
Dlang this this before. You have classes and struts, with different semantics.
- pjmlp 4mo ago
  Unfortunately D will remain a niche language due to various reasons, and is D not Dlang.

by cm2187 4mo ago

pjmlp 4mo ago

The problem is how to do it without breaking ABI, 30 years of Maven Central is very relevant, Java isn't doing a Python over value types.

cm2187 4mo ago
But if you define a new type, how is that breaking backward compatibility?
- pjmlp 4mo ago
  Because that is missing the point. All the types that are value types in semantics, e.g. Optional, should be proper value types on Valhalla. Additionally, they should be compatible with existing code that expects them as parameters, fields,.... without being recompiled from source. If it is a complete new type without backwards compatibility, no one is going to adopt it, other than a few niche cases.
- gf000 4mo ago
  Well, my old code can have a List<Object>, and I can pass my new type into it and have it do some operations. Let alone with reflection - so backwards compatibility is more complex than that. As for structs, Java avoids e.g. tearing issues with making them immutable, while it is easy to optimize it to local modification under the hood.

Someone 4mo ago

> how to insert struct in an object oriented language as an intractable problem, whereas a good implementation with .net (as far as I can tell) has been out there for nearly 30 years. And C# was shameless about stealing from other languages. I think (but may be wrong) their concerns are about the insert part. C# always had structs, Java wants to add them in a backward-compatible way. They want, for example, existing generic container classes pulled in from a .jar (i.e. already compiled) to support Java value types.

Zardoz84 4mo ago

Dlang this this before. You have classes and struts, with different semantics.

pjmlp 4mo ago
Unfortunately D will remain a niche language due to various reasons, and is D not Dlang.