Cello VS CompCert

Yes, that's C. C macros can take you quite far. Unfortunately because it's just a bunch of macros, it's quite brittle. Like high level abstractions created with macros in assembly language. You have to do all the checking and reasoning about it since the compiler cannot.

[1] https://libcello.org/

It took me a long time to understand, coming from higher level programming, that a lot of exactly that "higher level" is just systematic fat pointer conventions. And because pointers-with-metadata is not a first-class language construct, we invent all these languages that codify a particular fat pointer convention. Cello is an example of what kinds of abstractions can be built on top of a tiny little bit of (non-native) fat pointer convention.

There is a lightweight object oriented extension to C called Objective-C [1] that unfortunately never gained much traction outside the NeXT/Apple ecosystem. There is also Cello [2].

[1] https://en.wikipedia.org/wiki/Objective-C

[2] https://github.com/orangeduck/Cello

Regular expressions library to validate information before dumping to rocksdb.

https://www.gnu.org/software/libc/manual/html_node/Regular-E...

Non-critical implimentation fun, use cello [1] for 'gawk' functionality in C with C++ objects/classes.

[1] https://libcello.org/

You can achieve a fairly decent runtime safety for some types of project. Check out libcello and my own monster (libstent, lame presentation).

towards lisp related data structures / algorithms (aka recursive tree data structures & algorithms).

So, no distinction between metadata vs. structual storage unless noted.

Anything beyond that tends towards masters & upper level undergraduate level material. aka review the implimentation of a programming language for algorithm & data structure usage per language features.

aka Autonoma / regular expressions backround: Lisp in Small Pieces by Christian Queinnec; ; https://github.com/aalhour/awesome-compilers; On Lisp by Paul Graham; Let over Lambda by Doug Hoyte; C 'macro's pushed to maximum effect : https://libcello.org/

    Left out Comparison of languages; Transform from lang a to lang b; and language implimentation as discussions tend to assume masters / upper level undergraduate knowledge

with skills like this, mind to push cello forward? https://github.com/orangeduck/Cello really like it but not skillful enough to do it myself.

A big problem is that proving that transformations preserve semantics is very hard. Formal methods has huge potential and I believe it will be a big part of the future, but it hasn't become mainstream yet. Probably a big reason why is that right now it's simply not practical: the things you can prove are much more limited than the things you can do, and it's a lot less work to just create a large testsuite.

Example: CompCert (https://compcert.org/), a formally-verified compiler AKA formally-verified sequence of semantics-preserving transformations from C code to Assembly. It's a great accomplishment, but few people are actually compiling their code with CompCert. Because GCC and LLVM are much faster[1], and have been used so widely that >99.9% of code is going to be compiled correctly, especially code which isn't doing anything extremely weird.

But as articles like this show, no matter how large a testsuite there may always be bugs, tests will never provide the kind of guarantees formal verification does.

[1] From CompCert, "Performance of the generated code is decent but not outstanding: on PowerPC, about 90% of the performance of GCC version 4 at optimization level 1"

Also a C compiler (https://compcert.org/). I did exaggerate bit in saying that anything non-trivial is "nearly impossible".

However, both CompCert and sel4 took a few years to develop, whereas it would only take months if not weeks to make versions of both which aren't formally verified but heavily tested.

From my experience, while many MCUs have settled for the big compilers (GCC and Clang), DSPs and some FPGAs (not Intel and Xilinx, those have lately settled for Clang and a combination of Clang and GCC respectively) use some pretty bespoke compilers (just running ./ --version is enough to verify this, if the compiler even offers that option). That's not necessarily bad, since many of them offer some really useful features, but error messages can be really cryptic in some cases. Also some industries require use of verified compilers, like CompCert[1], and in such cases GCC and Clang just don't cut it.

[1]: https://compcert.org/

CompCert sends its regards

But that's fine, because we can do even better with things like the CompCert C compiler, which is formally proven to produce correct asm output for ISO C 2011 source. It's designed for high-reliability, safety-critical applications; it's used for things like Airbus A380 avionics software, or control software for emergency generators at nuclear power plants. Software that's probably not overly sophisticated and doesn't need to be highly optimized, but does need to work ~100% correctly, ~100% of the time.

For context, CompCert is a formally verified compiler. My former advisor helped with a fuzzer called CSmith which found plenty of bugs in GCC and LLVM but not in CompCert.

Does anybody know how does this compare to https://compcert.org/ ?

This is a common property for proof-oriented languages. Coq shares this property for instance, and you can write an optimizing C compiler in Coq: https://github.com/AbsInt/CompCert .