disassemble

static VALUE
iseq_s_disasm(VALUE klass, VALUE body)
{
    VALUE ret = Qnil;
    rb_iseq_t *iseq;
    extern rb_iseq_t *rb_method_get_iseq(VALUE body);

    rb_secure(1);

    if (rb_obj_is_proc(body)) {
        rb_proc_t *proc;
        VALUE iseqval;
        GetProcPtr(body, proc);
        iseqval = proc->block.iseq->self;
        if (RUBY_VM_NORMAL_ISEQ_P(iseqval)) {
            ret = rb_iseq_disasm(iseqval);
        }
    }
    else if ((iseq = rb_method_get_iseq(body)) != 0) {
        ret = rb_iseq_disasm(iseq->self);
    }

    return ret;
}