Function expr_context_add_function 

#[unsafe(no_mangle)]
pub extern "C" fn expr_context_add_function(
    ctx: *mut ExprContext,
    name: *const c_char,
    arity: usize,
    func: NativeFunc,
) -> i32

Add a native function to the context

Parameters

• ctx: The context
• name: Function name (must be valid UTF-8)
• arity: Number of arguments the function expects
• func: Function pointer

Returns

0 on success, non-zero on error