How I wrote a self-hosting C compiler in 40 days

For anyone interested in compiler writing and looking for a good resource to start, probably one of the best is the "Dragon Book":

http://www.amazon.com/Compilers-Principles-Techniques-Tools-...

I highly recommend it, but it's heavy stuff. There are probably simpler guides out there that just cover the basics.

Please stop recommending the Dragon Book already. It is not just heavy, it is mostly outdated and irrelevant.

There's quite a few decent alternatives. I often suggest Wirth's Compiler Construction and Oberon sources because they're straightforward lessons plus give experience with Wirth style of simple, safe, efficient languages. Then, they can improve the Oberon System or compilers for personal projects and improvement.

That said, I typically recommend compilers get written in an ML or LISP given it's so much easier to do in those languages. Ocaml and Racket are my main recommendations for modern work. One can also use techniques for deriving imperative code from functional programs if one wants to re-implement that compiler in specific imperative language on a machine. The constructs are even straight-forward enough for macro assembly for those that want to understand it down to bare metal.

I definitely agree with ML and OCaml, but why do you recommend Lisp for compiler work? I love working withs Lisps, but how do you deal with dynamic typing bugs in compiler work? I prefer OCaml/Haskell/ML for its really strong static type checking for compiler work. Just curious though...

ML got ADTs and static type guarantees, but Lisp got macros, which allows to implement things like http://andykeep.com/pubs/np-preprint.pdf - which is significantly less boilerplate than in ML. An ideal language for compilers would have combined both properties, but to make it happen, an expression problem must be solved first.

See a relevant discussion here from not long ago:

https://news.ycombinator.com/item?id=10712566

A commenter elsewhere said Racket had ADT's with langplai but also with langracket via subtypes of struct type with match macro. Said it was same style of programming.

So that's static typing (Typed Racket) and macros for sure. Possibly ADT's depending on whether you object to claim above. Should cover your list of requirements.

The problem here is that a single variant tag does not uniquely define a type, as all such type systems expect.