The type checker for TypeScript is >33,500 lines of handwritten code in a single file, which is getting up there for a high-level language: https://github.com/m

The type checker for TypeScript is >33,500 lines of handwritten code in a single file, which is getting up there for a high-level language: https://github.com/microsoft/TypeScript/blob/master/src/compiler/checker.ts https://github.com/microsoft/TypeScript/blob/master/src/comp...