Opened 11 years ago

Closed 7 years ago

#81 closed proposed-project (wontfix)

Implement a better type checker for yhc

Reported by: malcolm.wallace Owned by: none
Priority: OK Keywords: types, compilers
Cc: Difficulty: 1 person Summer
Mentor: not-accepted Topic: YHC

Description (last modified by KennKnowles)

The implementation of type inference in yhc (also used in nhc98) is occasionally incorrect, always difficult to understand and modify, and entirely undocumented. As a result, there is no hope of extending it to deal with multi-parameter type classes, functional dependencies, associated types, GADTs, rank-N, or any of the other exciting and widely-used type-system extensions. The solution - rip it out and replace it completely. There are a few key requirements: it must be maintainable, it must be correct, it must give reasonable error messages. Speed is not a goal.

Ideally, you will also implement one or more of the extensions noted above. There are opportunities to engage with cutting-edge type techniques like constraint-based resolution, or just to go for plain and simple H-M-style.

Interested Mentors

  • Malcolm Wallace <malcolm.wallace@…>

Interested Students

  • Charles Blundell <blundellc@…>
  • Kenn Knowles <kknowles@…>

Change History (11)

comment:1 Changed 11 years ago by malcolm.wallace

  • Description modified (diff)

comment:2 Changed 11 years ago by paolo

  • Summary changed from implement a better type checker for yhc to Implement a better type checker for yhc

comment:3 Changed 11 years ago by paolo

  • Description modified (diff)

comment:4 Changed 11 years ago by Leon P Smith

  • Description modified (diff)

comment:5 Changed 11 years ago by twanvl

  • Description modified (diff)

comment:6 Changed 10 years ago by malcolm.wallace@…

  • Description modified (diff)

comment:7 Changed 10 years ago by simonmar

  • Topic changed from GHC to YHC

comment:8 Changed 10 years ago by cb

  • Description modified (diff)

comment:9 Changed 10 years ago by KennKnowles

  • Description modified (diff)

comment:10 Changed 9 years ago by nominolo

  • Priority set to OK

In 2007 a type-checking library was developed. Having a library to type-check Haskell-programs would be nice. Having it independent of GHC not a bad idea either.

comment:11 Changed 7 years ago by dons

  • Resolution set to wontfix
  • Status changed from new to closed

Too old.

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