Representing optics by the set of actions they support. - ActionSetOptics.hs

Personal Blog

I enjoy using a type system to help make sure my term level code is unimpeachably correct. This is where my interest in writing the singletons library came from. This library allows you to write so…

Can I convince the compiler that a constraint is always satisfied by the type synonyms in a closed type family? The family is indexed by a finite set of promoted values.

Something along the lines ...

Lenses are a fascinating subject. Edward Kmett’s lens library is an indispensable tool in every Haskell programmer’s toolbox. I set out to write this blog post with the goal of describi…

W-types, following the Agde code here: https://www.e-pig.org/epilogue/?p=324 - W-types.hs

Summary: We have a version of mapM for IO that takes O(1) stack and is faster than the standard Haskell/GHC one for long lists. The stand...

This short talk introduces GHC's representation of constraints in its constraint solver. This is a good place to start if you're interested in how the typechecker works or considering extending it. The talk also doubles as an Experience Report as a typechecker…