C4: C in Four Functions (2014)
I unironically love this code. We used it as a starting point (or rather, the same design; we wrote in Go) for reversing challenges at our last startup, symbolically evaluating the stack machine bytecode to generate AVR.<p>The trick to reading it:<p>* next() is the lexer<p>* expr() is a precedence-climbing expression parser<p>* stmt() parses statements and generates code<p>* main() has the virtual machine loop.