Interoperability

Jule can interop with C++. A code written in C++ compatible with Jule can be transferred to Jule, used and compiled without any problems. Everything needed is readily available, as JuleC imports APIs by default to every generated code.

Using External Definitions

C++ links are stored separately. So to access C++ definitions it is necessary to use the C++ scope. The keyword extern is used to use the C++ scope. The external identifier can be used after the expression extern..

For example:

extern.myVariable

extern.myStruct{}

extern.myFunction(x, y, z)

Example to Interoperability

sum.hpp

#include "api/jule.hpp"

__jule_Int sum(const __jule_Slice<__jule_Int> slice) {
    __jule_Int total = 0;
    for (const __jule_Int x: slice)
        total += x;
    return total;
}

main.jule

extern use "sum.hpp"

extern fn sum([]int): int

fn main() {
    let numbers = [1, 2, 3, 4, 5, 6, 7, 8]
    let total = extern.sum(numbers)
    println(total)
}

The above example demonstrates the interoperability of Jule with a C++ function that returns total of all values of an integer slice. The C++ header file is written entirely using the Jule API. The Int, and Slice types used are part of the API. The Int data type is equally sensitive to system architecture as in Jule. The Jule source code declares to use sum.hpp first and binds the C++ function in it to Jule accordingly. Then a call is made from Jule and the result of the function is written to the command line.