c4

There are some mini typed functional languages here - https://plzoo.andrej.com/ Although they are implemented in OCaml, which feels like more magic than say a Forth or Lisp written in C. In C you can still "see" how it runs on hardware I think Standard ML is actually the "usable mini ML" These types of languages will always be bigger than Lisp/Forth/Tcl, because they require lexer /parser / type checker / GC runtime --- Although I would like to see someone do the smallest possible C version of an ML Something like c4 - C in 4 Functions (https://github.com/rswier/c4) - which actually has a type checker! (which is hard to see on first reading)

The C4 compiler is certainly fascinating and worth studying but don't believe that swieros's C compiler is based on that judging by their code [1][2]. There are similarities of course but well they are compiling the same language after all using some similar standard techniques like recursive descent parser [3]. Anyways, C4 is also very cool and focused on minimalism. Swieros's compiler seems much more extensive and even includes #define as the other comment mentioned and va_args. [1] https://github.com/rswier/swieros/blob/master/root/bin/c.c [2] https://github.com/rswier/c4/blob/master/c4.c [3] https://en.wikipedia.org/wiki/Recursive_descent_parser

The C4 compiler [https://github.com/rswier/c4] is a self-hosting compiler for a subset of the C programming language that produces executable x86 code. You can understand and audit this code in a couple of hours (its 528 lines). It could be an interesting exercise to bootstrap up from something like this to a working linux environment based solely on source code compilation : no binary inputs. Of course a full linux environment has way too much source code for one person or team to audit, but at least it rules out RoTT style binary compiler contamination.

c4 - C in four functions: https://github.com/rswier/c4/ c4x86 - JIT compiler for x86 in 86 lines: https://github.com/EarlGray/c4

I was surprised to see nodes still have two pointers ("references") given that you now know that that the first pointer will always point exactly to the next node. I've see https://github.com/rswier/c4 use that. Granted it doesn't make for the most readable code, but it's even smaller and faster.

C4 comes to mind (C in 4 functions), https://github.com/rswier/c4. have you considered adding a backend for LLVM? perhaps a bit heavyweight, but it could be a good way to get C/C++, fortran, rust, etc. if that's something you'd like!

Great question. Here are some candidates: * https://github.com/rswier/c4 * https://github.com/Fedjmike/mini-c * https://github.com/rui314/8cc * https://github.com/rui314/chibicc * https://github.com/aligrudi/neatcc Some of them are actually interpreters, and I personally would be interested in actual compilers that generate machine code.

...or in other words, "they're hard only because you make them hard". That said, I think C4 makes a better example of how simple it can be: https://github.com/rswier/c4/blob/master/c4.c (Previously on HN at https://news.ycombinator.com/item?id=8558822 and https://news.ycombinator.com/item?id=22353532)

I agree strongly about the "not magic" part, and think that there's no better way to show that than to have the goal of the course be to create a self-compiling compiler. As a matter of fact, a whole course could be devoted to the study of this masterpiece: https://github.com/rswier/c4

I think c4 (a C compiler in four functions, hence the name) is pretty neat. https://github.com/rswier/c4/blob/master/c4.c

I made a branch of c4 that includes struct support. I should probably add it to the master branch so it gets more visibility: https://github.com/rswier/c4/blob/switch-and-structs/c4.c