method-defined.c

#include <stdbool.h>
#include <stdio.h>

#include <mruby.h>
#include <mruby/value.h>

/* Check if a certain method is defined using respond_to? */
static bool method_defined(mrb_state *mrb, char *method_name) {
    // Create a symbol corresponding to the method name
    mrb_sym method_sym = mrb_intern_cstr(mrb, method_name);

    return mrb_obj_respond_to(mrb, mrb->object_class, method_sym);
}

mrb_value mrb_example_method(mrb_state *mrb, mrb_value self) {
    // Empty method...

    return mrb_nil_value();
}

int main(int argc, char *argv[]) {
    mrb_state *mrb = mrb_open();
    if (!mrb) {
        fprintf(stderr, "Couldn't initialize MRuby\n");
        return 1;
    }

    // We define a dummy method
    mrb_define_method(mrb, mrb->kernel_module, "example_method", mrb_example_method, MRB_ARGS_NONE());

    // Checking for a method
    if (method_defined(mrb, "example_method")) {
        printf("'example_method' found!\n");
    }

    mrb_close(mrb);
    return 0;
}