func isLowerVowel(r rune) bool {
	switch r {
	case 'a', 'e', 'i', 'o', 'u', 'y', 'æ', 'ø', 'å':
		return true
	}
	return false
}
Checks if a rune is a lowercase Norwegian vowel.
package norwegian
import (
	"github.com/kljensen/snowball/romance"
	"github.com/kljensen/snowball/snowballword"
)
func r1(word *snowballword.SnowballWord) (r1start int) {
	r1start = romance.VnvSuffix(word, isLowerVowel, 0)
	if r1start < 3 && len(word.RS) >= 3 {
		r1start = 3
	}
	return
}