JSCPP, a simple C++ interpreter written in JavaScript | Hacker News Reader

JSCPP, a simple C++ interpreter written in JavaScript

github.com

98 pointsturrini31 comments

also relevant is cling, made by the folks at CERN

https://root.cern.ch/cling

this is neat. I noticed that with this we get Read–eval–print loop for C++. Which would make it really useful in an ide like light table.

A similar project, also good for educating but within a jupyter notebook for c++

https://github.com/QuantStack/xeus-cling

* A subset of C++.

I was going to say, "Jesus Christ did one guy actually manage to write a fully standards-conformant C++ parser?"

I know of one guy who did, as well as inventing the D language, and he also visits HN and posts semi-regularly --- http://walterbright.com/

A simple C++ interpreter is an oxymoron.

It's c++ without the "object-oriented features," so that could be fairly simple.

That's called C.

It could still support e.g. function templates (not sure if it actually does).

C is C++ minus object-oriented features, increased type-safety, template meta-programming, lambdas, and many more features.

Not true, C has features missing from C++.

Which?

https://www.quora.com/What-features-are-present-in-C-but-not...

There is a more complete answer with a link but quickly : restrict, designated initializers, generic macros...

So, are there situations where one would use C over C++? I don't know C++, and only learned C while catching up on my fundamentals.

Right, the useless cruft that makes your program impossible to read, let alone reason about

Ha! The lambdas and tools surrounding them in C++11 and later have vastly improved the ability to make programs much easier to read and reason about.

yes, I guess all those C++ programs don't exist and C++ programmers don't actually read or write any programs.

Hardly. Compare std sort to qsort and tell me that it's superior.

Is this the cruft that gets reinvented in C whenever the project grows complex enough?

Something like: any sufficiently complicated C program contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of C++'s features.

I didn't write the README.

Strictly speaking, C++ is not anymore a superset of C. Mostly syntatic sugar but still, some C code can not be parsed by C++. But yeah, i know what you mean, i guess this is a bastard of C and C++?

C++ was never a superset of C. The same keywords mean different things, character literals are different types, void pointer assignment works differently, etc.

No, this isn't C either. The following doesn't work:

  struct Bob {
    int a;
  };
  int main() {
    int a;
    struct Bob x;
    x.a = 3;
    return 0;
  }

So when they say "without object oriented features" they seem to mean: "No extendable type system". Which does make this a lot simpler of a language.

The example uses the iostreams header instead of cstdio. Not sure how this would work without object-oriented features.

It seems like some of the C++ library features are special-cased.

From the Q&A section of the readme:

"Which notable features are not implemented yet?

    > Object-oriented features"

"Which libraries are supported?

    > iostream (only cin and cout and endl)"

This appears to be a proof of concept, for the purposes of learning and exploration. From the README:

"Currently, it is mainly for educational uses for a MOOC course I am running (and fun)."

"Which features are implemented? (Most) operators"

Couldn't find in readme if templates are supported.

It doesn't even support structs/classes.

edit: Templated functions don't work either.

But why? Most js engines (or at least V8) are written in c++.

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