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.

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Someone 4 hours ago | parent | next [-]

> 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.

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pjmlp 4 hours ago | parent | prev | next [-]

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.

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cm2187 4 hours ago | parent [-]

But if you define a new type, how is that breaking backward compatibility?

	▲	pjmlp 3 hours ago \| parent [-]
		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.

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Zardoz84 3 hours ago | parent | prev [-]

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