CONTRIBUTING.md

Contributing

Most low-hanging fruit in CXBQN involves system functions (such as •FChars) that have not been implemented yet. To add a system value, see include/cxbqn/sys.hpp, particularly towards the bottom. Here I have many system functions already declared, and defined in src/sys/. If the system function requires a value from the runtime environment (such as the runtime itself, or the compiled BQN formatter), simply take that item as a constructor and pass the field when constructing the system function in src/sys/sys_function_resolver.cpp.

The system function •Exit is a great example of a simple system function. The constructor takes no arguments, so it uses a macro in include/cxbqn/sys.hpp, but it's declaration is as simple as:

// see include/cxbqn/sys.hpp
struct Exit : public Function {                                                   
  std::ostream &repr(std::ostream &os) const override {                      
    return os << "•Exit";                                                
  }                                                                          
  O<Value> call(u8 nargs = 0, std::vector<O<Value>> args = {}) override;     
};                                                                           

and the definition is extremely simple as well:

// see src/sys/exit.cpp
O<Value> Exit::call(u8 nargs, std::vector<O<Value>> args) {
  auto n = dynamic_pointer_cast<Number>(args[1])->v;
  std::exit(n);
}

To find a system function to write, see the specification for system values and find one not already in include/cxbqn/sys.hpp. Feel free to email me at [email protected] with questions, or better yet, join the Matrix server.

I would also love help implementing a garbage collector, however this will be far more involved.