It's worth pointing out that Lisp is homoiconic, meaning that the code you see has the same structure as its AST, so writing a parser for a Lisp is pretty trivial and is part of the reason why this compiler looks super short. Other languages like C, however...
The "code generator" part of this compiler doesn't do much, since it only translates from one high level language to another, not machine code which would understandably be far more complicated, as other commenters have pointed out.
This is a compiler from an altitude of 50km in the stratosphere, and won't actually teach you much about real world compilers that do so much more under the hood. Sorry to be Mr. Cranky HN commenter (ok, I'm not sorry).
The "code generator" part of this compiler doesn't do much, since it only translates from one high level language to another, not machine code which would understandably be far more complicated, as other commenters have pointed out.
This is a compiler from an altitude of 50km in the stratosphere, and won't actually teach you much about real world compilers that do so much more under the hood. Sorry to be Mr. Cranky HN commenter (ok, I'm not sorry).