Making a Type Checker/LSP for Nix
Summary
A detailed overview of Tix, a custom type checker and LSP for Nix, built to provide strong typing, autocompletion, and jump-to-definition for Nix code. The article explains the underlying type systems (Hindley–Milner, SimpleSub with negation types), stubs, context-based typing, and testing strategies, plus notes on performance and integration with AI tooling like Claude.