A new interface for GHC typechecker plugins and type-family rewriting
GHC typechecker plugins are a useful mechanism through which users can introduce knowledge into GHC’s typechecker, such as augmenting GHC with a solver for propositional logic , Presburger  or Peano arithmetic , dimensional analysis , regular grammars .
However, it can be difficult to maintain a typechecker plugin to work across GHC versions, as internal aspects of GHC’s typechecker change.
In this talk, I present a new interface for typechecking plugins which aims to solve this problem. This includes:
- a review of the existing type-checking plugin functionality,
- an illustration of the new functionality for rewriting type-family applications,
ghc-tcplugin-apilibrary which aims to provide a stable interface for authors of typechecking plugins.
 Matt Noonan - Ghosts of Departed Proofs (https://doi.org/10.1145/3299711.3242755)
 Hiromi Ishii - ghc-typelits-presburger library (https://hackage.haskell.org/package/ghc-typelits-presburger)
 Christiaan Baaij - ghc-typelits-natnormalise library (https://hackage.haskell.org/package/ghc-typelits-natnormalise)
 Adam Gundry - A Typechecker Plugin for Units of Measure (https://doi.org/10.1145/2804302.2804305)
 Oleg Grenrus - Regular Expressions of Types (http://oleg.fi/gists/posts/2018-09-13-regular-expressions-of-types.html)
Sun 22 AugDisplayed time zone: Seoul change
23:30 - 01:00
|Generalization is hard, but somebody's got to do it|
Richard A. Eisenberg Tweag
|A new interface for GHC typechecker plugins and type-family rewriting|
Sam Derbyshire TweagMedia Attached
|The Dynamic Haskell Plugin for GHC|
|GHC Status update|
Simon Peyton Jones Microsoft, UKFile Attached