for r := rune(0); r <= unicode.MaxRune; r++ {
		if isSpace(r) != unicode.IsSpace(r) {
			t.Errorf("IsSpace(%U)=%t incorrect", r, isSpace(r))
			n++
			if n > 10 {
				return
			}
		}
	}
}

func TestSplitRegexp(t *T) {
	res := func(s ...string) filterMatch { return simpleMatch(s) }
	alt := func(m ...filterMatch) filterMatch { return alternationMatch(m) }
	testCases := []struct {
		pattern string
		result  filterMatch
	}{