max

static VALUE
range_max(VALUE range)
{
    VALUE e = RANGE_END(range);
    int nm = FIXNUM_P(e) || rb_obj_is_kind_of(e, rb_cNumeric);

    if (rb_block_given_p() || (EXCL(range) && !nm)) {
        return rb_call_super(0, 0);
    }
    else {
        VALUE b = RANGE_BEG(range);
        int c = rb_cmpint(rb_funcall(b, id_cmp, 1, e), b, e);

        if (c > 0)
            return Qnil;
        if (EXCL(range)) {
            if (!FIXNUM_P(e) && !rb_obj_is_kind_of(e, rb_cInteger)) {
                rb_raise(rb_eTypeError, "cannot exclude non Integer end value");
            }
            if (c == 0) return Qnil;
            if (!FIXNUM_P(b) && !rb_obj_is_kind_of(b,rb_cInteger)) {
                rb_raise(rb_eTypeError, "cannot exclude end value with non Integer begin value");
            }
            if (FIXNUM_P(e)) {
                return LONG2NUM(FIX2LONG(e) - 1);
            }
            return rb_funcall(e, '-', 1, INT2FIX(1));
        }
        return e;
    }
}