scala/scala3
Scala3
Scala 3 is an open-source, statically typed programming language that compiles to JVM bytecode, combining object-oriented and functional programming paradigms. Its core identity is defined by a sophisticated type system that includes traits, generics, union types, and a dependent object type system where types can depend on runtime values through path-dependent and singleton types.
The language distinguishes itself through several advanced type-level and metaprogramming capabilities. It features a contextual abstraction mechanism using given instances and using clauses for compile-time implicit resolution, inline metaprogramming with staged evaluation on typed abstract syntax trees, and match type computation for compile-time conditional type definitions. Scala 3 also enforces multiversal equality to prevent unintended type comparisons, supports opaque type aliasing that hides underlying representations while maintaining type safety, and employs a trait linearization model for deterministic method resolution in mixin composition.
Beyond its type system, Scala 3 provides a complete development toolchain including a compiler that translates source code into executable bytecode, a standard library, and a formal language specification. The language supports interactive evaluation through a REPL, script compilation and execution from the command line, and toolchain installation management. It also offers comprehensive educational resources such as structured language lessons, in-depth feature guides, video series, and recorded conference talks, along with migration guidance for moving codebases from Scala 2 to Scala 3.
Features
- JVM Bytecode Compilers - Compiles Scala 3 source code into Java bytecode that runs on the Java Virtual Machine.
- Contextual Implicit Resolutions - Implements a contextual abstraction mechanism using given/using clauses for compile-time implicit resolution.
- Type-Directed Implicit Resolutions - Resolves given instances and using clauses through compile-time type-directed lookup for contextual parameters.
- Sealed Hierarchy Desugarings - Compiles enum definitions into sealed class hierarchies with union type support for algebraic data types.
- Open Source Software - Developed and maintained by the Scala community under an Apache 2.0 license with an open contribution process.
- Functional Programming Concepts - Implements functional programming concepts including immutability, higher-order functions, and pattern matching.
- Source-to-Bytecode Compilers - Translates Scala 3 source code into executable bytecode, enabling developers to build and run applications.
- Algebraic Data Type Enumerations - Expresses algebraic data types through enum definitions that desugar into sealed class hierarchies with union types.
- Metaprogramming & Macros - Provides inline metaprogramming with staged evaluation on typed abstract syntax trees for compile-time code generation.
- Path-Dependent Type Systems - Enables types that depend on runtime values through path-dependent and singleton types for precise reasoning.
- Representation-Hiding Type Aliases - Hides underlying type representations while maintaining type safety through controlled visibility and separate compilation.
- Scala - An open-source, statically typed language combining object-oriented and functional programming for the JVM.
- Interactive Development Environments - Provides a built-in REPL for interactive code evaluation and experimentation.
- Deterministic Method Resolution Orders - Determines method resolution through a deterministic linearization order of trait mixins for super call chains.
- Statically Typed Languages - Enforces type safety at compile time with a sophisticated type system including traits, generics, and union types.
- Standard Libraries - Delivers a collection of reusable classes and functions that support common programming tasks.
- Dependent Object Type Compilers - Compiles Scala 3 source code into JVM bytecode using a dependent object type system and simplified syntax.
- Linearized Trait Mixins - Linearizes trait mixins following a specific ordering rule for deterministic method resolution and super call chains.
- Compile-Time Equality Guards - Enforces type-safe equality comparisons through a canEqual method preventing unintended type comparisons at compile time.
- Type-Safe Equality Enforcements - Enforces type-safe equality comparisons through a canEqual method preventing unintended type comparisons at compile time.
- Type-Level Conditional Logic - Enables type-level pattern matching for compile-time conditional type definitions and recursive type reduction.
- Language Release Highlights - Highlights the new language features and improvements introduced in the language.
- API Documentation - Ships searchable API documentation for every version of the standard library.
- API Documentation Generators - Produces API documentation for projects using the Scaladoc tool with new features.
- Source-Level Dependency Directives - Declares library dependencies in source files with directives resolved automatically at compile time.
- Progressive Lesson Series - Teaches the language through a series of short, structured lessons for progressive learning.
- Bite-Sized Tutorials - Introduces core language features through bite-sized lessons and short tutorials for newcomers.
- Language Specifications - Publishes a formal language specification defining syntax and semantics for tool builders and developers.
- Language Version Migrations - Provides a guide that helps move code from an older version of the language to a newer one.
- API Documentation Browsers - Provides searchable API documentation for every version of the standard library.
- Learning Resources - Offers structured language lessons and bite-sized tutorials for learning Scala 3 fundamentals.
- Migration Guides - Ships a dedicated migration guide for moving codebases from Scala 2 to Scala 3.
- Advanced Feature Documentation - Offers comprehensive documentation covering many of the language's advanced features.
- Idiomatic Coding Standards - Provides a style guide with conventions for writing clean, idiomatic code.
