Comment by jillesvangurp

Why not:

- The C-compiler. AI tools work better if their automated feedback loop via tools includes feedback on correctness, safety, etc. The C compiler is not great at that. It requires a lot of discipline from the programmer. There mostly isn't a compile time safety net.

- Macros add to this mess. C's macros are glorified string replacements.

- Automated tests are another tool that helps improving quality of vibe coded code. While you can of course write tests for C code, the test frameworks are a bit immature and it's hard to write testable code in C due to the lack of abstractions.

- Small mistakes can have catastrophic consequences (crashes, memory overflows)

- A lot of libraries (including the standard library) contain tools with very sharp edges.

- Manual memory management adds a lot of complexity to code bases and the need for more discipline.

- Weak/ambiguous semantics mean that it's harder to reason about code.

There are counter arguments to each of those things. Compilers have flags. There are static code analyzers. And with some discipline, it gets better. You could express that discipline in additional instructions for your agent. And of course people do test C code. There just are a lot of projects where none of that stuff is actively used. Vibe coding on those projects would probably be a lot harder than on a project that uses more structured languages and tools.

All these things make it harder to work with C code for humans; and for AIs. But not impossible of course. AI coding models are getting quite good at coding. Including coding in C.

But it makes it a poor default language for AI coding. The ideal vibe coding language for an AI would be simple, expressive, have great tools and compilers, fast feedback loops, etc. It means the AI has less work to do: shorter/faster feedback loops, less iterations and reasoning to do, less complex problems to solve, less ambiguity, entire categories of bugs that are avoided, etc. Same reasons as to why it is a poor choice for most human programmers to default to.