Valhalla - Where Are We?

Project Valhalla wants to heal the rift in #Java’s type system between classes and primitives by introducing value classes, which “code like a class, work like an int“ and offer a flat and dense memory layout. Java’s epic refactor, as it has been dubbed, has been going on for 10 years but is now entering the home stretch. At #JVMLS 2024, Java Language Architect Brian Goetz explained the proposed solution: value classes (already available in an EA build), null-restricted types, beefed up definite assignment analysis, and strict initialization. Chapters 0:00 Executive Summary 7:19 Brief History 15:26 Value Classes ⟪~⟫ Object Identity 24:03 Null-Restricted Types ⟪~⟫ Nullability 31:53 Strict Initialization 35:06 The Cascade of Simplification 40:19 Serialization 41:13 Flattening & Tearing Values 47:10 Mopping up