Compiler and linker are 186,865 lines of code. My `hcs` branch which adds hot code swapping support for Linux (a companion PoC to the author of the OP) is 328 a

Compiler and linker are 186,865 lines of code. My `hcs` branch which adds hot code swapping support for Linux (a companion PoC to the author of the OP) is 328 additions and 18 deletions [1]. And about 200 lines of those are adding ptrace constants to the std lib and a simple socket server to the compiler just as a method of issuing commands while the stdio is locked up in the running application. Crazy right? This is because incremental compilation & linking is actually the same problem as hot code swapping! This was just a natural fallout of the design of the compiler. Same deal with Jakub's hot code swapping branch. It's 257 additions and 9 deletions and has the same ~150 lines of adding the socket server [2]. So in answer to your question, the PoC adds about 150 lines to an 186,865 line codebase. [1]: https://github.com/ziglang/zig/compare/hcs https://github.com/ziglang/zig/compare/hcs [2]: https://github.com/ziglang/zig/compare/hcs-macos https://github.com/ziglang/zig/compare/hcs-macos