C³designer's blog

- C³ is a language, not a runtime system.

Not imposing a runtime is a good idea. That said, it should come with a good runtime to use as the default, otherwise it'd would make the language impossible to learn. Even C has its own runtime!

- Leave no room for a lower-level language below C³ (including assembler).

Really? And how are you going to write a function that does a system call?

What I call a "runtime system" would be something like the JVM. Don't worry, there will be plenty of available functions. As we speak, I'm designing the minimal system necessary to run my "hello, world" program.

About assembly-level coding, it's just a matter of syntax: instead of linking to object files generated from separate .s files, I would like to have an API that is a direct mapping of the instruction set of the machine with C³ syntax.

At least, in my quest for making C3 "all-purpose", I'm not adding a lot individual features. I'm focused on making general mechanisms to allow different needs to be fulfilled. I'm also planning on using these features myself to offer complete solutions for some niche, like education or games (because it's what I know best)

Reading your goals, etc, it seems we agree much on the philosophical side of things. The parsing choices you've made are right on, Keeping the language simple (no automated GC, awesome!).

Of course there's the detail level: some questions about syntax, examples, etc.

Some of my concerns, especially coming from c++ include:

- level of type checking and safety, especially regarding type promotion ('explicit' really has saved our bacon).
- allowing for heavy use of immutable paradigm (we rely heavily on "in place construction" support in the compiler and constify most everything).
- allowing editable arguments to be passed by reference only is bad for readability. Allow pass by const ref, value and addressof (or equivalent) ONLY.

some suggestions:
- const keywords for variables should always be to the right of what is being made const. I know lots of c and c++ programmers don't follow this but using this rule should make parsing much easier and i found that it was much easier to constify even more portions of types removing lots of stupid coding errors.

- There will be no implicit conversions at all.

- What do you mean by "in place construction"?

- Pass by const reference is the default. There is no pass by value (if the callee needs a copy, it must be done explicitly). Pass by reference will be explicit at the call site with the & operator, except for operators that are already explicit like +=, -=. etc.

The declarator syntax is much simpler in C³ than in C++ which means that there is no problem with const to the left of the type. In fact, the grammar does not allow const to the right...

http://carlo17.home.xs4all.nl/cpp/const.qualifier.html

All I ask is for consistency here. I've just been using the conventions in the above for 6.5 years now.

an example (chose vector but could be map, object, etc)

a function that creates a vector, populates it then returns it. *if* the vector is declared first in the function and the function only has a single exit point at the bottom returning that function some compilers are able to forego the vector copy and actually fill the vector from the code which called the function. C++0x I believe formalizes this with rvalue references (which look kind of messy to me).

somevec = genvec();

vector genvec()
{
vector res;
// fill vector res
return res;
}

I think you will like the way most temporaries are eliminated in C³! The rules are much saner than C++98's RVO (return value optimization) or C++11's rvalue references. In fact, in your example, if there is no side effect in the function, C³ would be able to do all the work at compile-time!