Speaker: Neha Sardana

For more see the table of contents

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General

• Aim: Code is clear like Amber
• Showed old release cadence ncluding 5 year gap from 2006-2011

Many projects

• Amber – small incrememenal language enhanceents
• Loom – lightweight concurrency and virtual threads
• Valhala – value types and generic collections
• Panama – native code

Goals of Amber

• Boost productivity – less boilerplate
• Improve code readability
• Support long term evolution
• Maintain language consistency

Preview features

• Experimental but final features
• Have to enable preview features to use

Local variable type inference

• var – JEP-286
• var for lambda parameters JEP-323
• variable names more important because don’t have the type

Data handling

• Records – 359, 384, 395
  • Data classes
• Immutable and final
• IdIeal for data transfer objects
• Sealed classes – JEP 360, 397, 409
• Controlled inheritance
• Improved code safety
• Enhanced pattern matching
• Text blocks – 355, 368, 378
• Multi line string simplification
• Improved readability
• Automatic formatting
• Remember when had to put SQL in a String
• String templates 430, 459, 465 – withdrawn)
• Not available in Java 23. Would have simplified string concat, improved safety and enhanced readability
• Withdrawn due to issues
• If some back, will have new design/syntax

Control flow

• Switch expressions 325, 354, 361
• Simplified syntax
• Return values
• Exhaustiveness checking
• Pattern matching for instance of 305, 375, 394
• Eliminates casting
• Improves readability
• Safer type handling
• Pattern matching for switch 406, 420, 427, 433, 441
• Some of the JEPs didn’t change; just wanted more user feedback
• Primitives types in patterns, instanceof, and switch 445
• preview in 23
• can use int to match instead of having to use Integer
• Record patterns – 405, 432, 440
• Declare record fields in same line so can use in instance of without having to reference
• Pattern matching for data decomposition
• Can use instance of and && in a lamdba; doesn’t have to be in if statement
• Works with instanceof and switch
• Unnamed patterns and variable 443, 456
• Use _ instead of name to show unused
• Clearer that want to ignore data
• Enhanced pattern matching flexibility
• Can use _ in lambda variable, catch block, etc as well

New language features

• Implicitly declared classes and instance main methods – 445, 463, 477
• In preview
• void main() – no class, no public/static/params
• println() instead of System.out – in void main(), get that static import without having to have the import
• Reduces boilerplate
• Module import declarations – 476
• In preview
• import module java.base;
• Simplifies module usage
• Let’s use classes in module.
• If conflict, need to explicitly import that class
• Statements before super -> Flexible constructor bodies 447, 482
• feature renamed between versions of Java
• Flexibile initialization
• Improved code flow
• Enhanced control

Future

• Derived record creation 468
• in preview
• allow extending records – dervices most values from original
• Person x – original with { email = “e”; };
• Simplify record inheritance
• Reuseable code

My take

I had seen this talk in NY and came to support Neha. It’s still good :). I like that she had a lot of examples. Mentioning Scala a lot was fine, More opportunities to learn..