Awesome experience with scala on eclipse
Questions!
Why am I Here?
Currently working on Metals as one of the main contributors as a part of the collaboration between VirtusLab and Scala Center.
Who is working on metals?
and many more contributors from the community!
Metals - Scala language server with rich ide features
Your favourite language in you favourite Editor
How does it work?
How does it work?
Pieces to the puzzle
- Build tools
- semantic information
- Scala presentation compiler
Pieces to the puzzle
- Build tools <- A LOT OF THEM
- semantic information
- SCALA PRESENTATION COMPILER
Build tools
Mill
Seed
Build tools
Mill
Seed
Bloop
- Bloop is a Scala build server
- Serves requests via build server protocol
- gives us information about the build
- uses json configuration files
Pieces to the puzzle
- Build tools <- connects VIA BSP
- semantic information
- SCALA PRESENTATION COMPILER
Pieces to the puzzle
- Build tools <- CONNECTS VIA BSP
- semantic information <- semanticDB, but on compile...
- SCALA PRESENTATION COMPILER
Compile on save
- "hot" Bloop compiler
- fast feedback
- same errors as in the build tool
- SemanticDB files created
Compile on save
Pieces to the puzzle
- Build tools <- CONNECTS VIA BSP
- semantic information <- semanticDB, we have bloop!
- SCALA PRESENTATION COMPILER
Pieces to the puzzle
- Build tools <- CONNECTS VIA BSP
- semantic information <- semanticDB, we have bloop!
- SCALA PRESENTATION COMPILER <- can end up in bad state
Scala presentation compiler
- We get it for free by depending on the scala compiler
- Used by Ammonite, Repl, ScalaIDE
- we can discard it whenever we want
- run in a separate thread
Pieces to the puzzle
- Build tools <- CONNECTS VIA BSP
- semantic information <- semanticDB, we have bloop!
- SCALA PRESENTATION COMPILER <- Discard thread with Pc
What is already implemented
- completions
-hover
- signature Help
- go to definition
- references
-diagnostics
-document Highlight
- document Symbol
- folding Range
- FORMATTING
- RANGE FORMATTING
- ON TYPE FORMATTING
- document Highlight
- tons of smaller features
In snapshot:
- implementation
- codeLens
- run/test
Metals in action - Completions
Metals in action - Definition/hover
Works also in eclipse Theia!
Go to:
https://gitpod.io/#https://github.com/tgodzik/metals-mill-sample
and try Metals for yourself!
New!
Available in latest SNAPSHOT
easier import
- Metals sends information about SemanticDB version.
- Bloop tries to resolve it and adds to workspace settings.
- SemanticDB files are created on compile.
Goto implementation
- new class inheritance index
- no noticable impact on indexing
- works with overloaded methods
- for workspace and library symbols
Goto implementation
Debug adapter protocol
- GENERIC DEBUGGER FOR A DEVELOPMENT TOOL
- implemented in Bloop
- Metals serves as proxy
- currently only run/test
Debug adapter protocol
run/test
Next on the roadmap
- go to type definition
- rename symbol
- debugging with breakpoints
- better test interface
- dotty (Scala 3) support
- pants support
Future work
Questions?
Recent Scala Days talk by Ólafur Páll Geirsson https://www.youtube.com/watch?v=MRQMylDxBJ8
Metals documentation:
Bloop documentation:
https://scalacenter.github.io/bloop/
Shout at me on Twitter: @TomekGodzik
Questions?
Awesome experience with Scala on Eclipse
By Tomek Godzik
