HacFreiburg2017/ListOfProjects

• purescript compiler, type and analysis related topics
• ghcjs, some language server protocol implementation
• Spock, PureScript
• Snowdrift.coop
• hayoo!, hunt
• simplexhc, ghc
• Not sure right now. Probably guide (https://guide.aelve.com/)
• I'm at beginner level, so would be willing to join to a project that matches my current skills.
• In general: projects using Scala, Docker, Microservices...

ghc/haddock

Revamp the haddock type-class specializer

For convenient display of type-class instances haddock inserts the instance head into the type-class methods type signatures. However in the current implementation haddock does no alpha-conversion on type variables if they are not bound by forall. See https://github.com/haskell/haddock/issues/654 for an example.

This is an easy starter ticket. Changes would be pretty local `rename` (see https://github.com/haskell/haddock/blob/master/haddock-api/src/Haddock/Interface/Specialize.hs#L229) and could be done in a few hours. If you are interested in this task talk to Alex Biehl.

Handle `pattern` exports

The PatternSynonyms extension introduced `pattern` exports which can be used to export single constructors of a data type without the data type itself. Currently when haddock sees a name in an export list it tries to find its corresponding declaration. From an ASTs viewpoint single data constructors do not have a declaration. Instead they are nested in its owning data declaration. See https://github.com/haskell/haddock/issues/653 for an example.

A fix would try to beef up `findDecl` to handle the case of a data constructor name by returning the owning data declaration (see https://github.com/haskell/haddock/blob/master/haddock-api/src/Haddock/Interface/Create.hs#L701). `mkExportDecl` then would prepare the constructor for rendering. If you are interested in this task talk to Alex Biehl.

Finish --show-interface

When debugging it is commonly needed to look into the generated haddock-interface files. https://github.com/haskell/haddock/pull/645 laid the groundwork for such a feature. It adds a command line parameter which dumps an interface file to json. If you are interested in this task talk to Alex Biehl.