I feel like I shouldn't be this proud of it, but I just wrote a recursive descent parser from scratch in one go in C and debugged a small problem (off by one error of course) using gdb; all in under half an hour.
@clementd They certainly are extremely handy. And apparently these people have even found a way to make them extremely performant, i.e., only about 50% slower than a bison generated parser: https://dl.acm.org/doi/epdf/10.1145/3409002