Motivation for this change

dotty-0.18.1

Notable Changes

Language

• Implement @main functions
• Allow infix operators at start of line
• Drop do while
• Alternative Syntax for Control Expressions
• Allow significant indentation syntax
• Change indentation rules to allow copy-paste
• Switch to the 2.13 standard library
• Allow collective parameters for extension methods
• Implement generic number literals

Metaprogramming

• Add toExprOfTuple in scala.quoted
• Make toExprOfTuple produce tuples with precise types
• Add quoted.Liftable[TupleN] with N > 22 to the stdlib
• Add quoted.Liftable[BigInt] and quoted.Liftable[BigDecimal] to the stdlib
• Add quoted ExprOps toExprOfSeq
• Re-contextualize Liftable.toExpr
• toExprOfTuple method with precise types
  -Factor out staging from the core of scala.quoted
• Add scala.quoted.Liftables to the stdlib
• Remove scala.quoted.QuoteError
• Create dotty-staging library

Type class derivation

• Add documentation for type class derivation
• Removed redundant Shape type
• Support implicit scope augmentation for Mirror

Other

• [DOC] Add ScalaDays 2019 talks
• Release sbt-dotty 0.3.4, future-proof isDotty
• In Scala.js mode, compile all lazy vals as thread-unsafe.

dotty: 0.19.0-RC1

Notable Changes

Syntax

• Make indentation significant in old-style control syntax
• Don't require colon after class or object signatures
• Replace the[...] by summon[...]
• Allow given bindings in patterns
• Replace delegate match with summonFrom.
• Switch to ? for wildcard types
• Require (...) around parameters of a lambda
• Drop old syntax styles for givens

Macros

• Upgrade to scala-library 2.13.1
• Detect macro dependencies within the current run
• Add dotty-staging.g8 in the staging documentation
• Intrinsify scala.compiletime.testing.typeChecks

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

cc @karolchmist