Mechanized type inference for record concatenation
Summary
This in-depth blog post analyzes mechanized type inference for biased record concatenation in Nix, tracing the Wand algorithm from historical roots to a practical, mechanizable approach. It details declarative and algorithmic semantics, constraint generation, and a substantial Haskell implementation, including field/row instantiation and a complete constraint solver. It also provides a companion GitHub project to test and reproduce the results.