english/common.go
func normalizeApostrophes(word *snowballword.SnowballWord) (numSubstitutions int) {
	for i, r := range word.RS {
		switch r {

		// The rune is one of "\u2019", "\u2018", or "\u201B";
		// equivalently, unicode code points 8217, 8216, & 8219.
		case 8217, 8216, 8219:

			// (Note: the unicode code point for ' is 39.)

			word.RS[i] = 39
			numSubstitutions += 1
		}
	}
	return
}
func normalizeApostrophes(word *snowballword.SnowballWord) (numSubstitutions int) {
	for i, r := range word.RS {
		switch r {

		// The rune is one of "\u2019", "\u2018", or "\u201B";
		// equivalently, unicode code points 8217, 8216, & 8219.
		case 8217, 8216, 8219:

			// (Note: the unicode code point for ' is 39.)

			word.RS[i] = 39
			numSubstitutions += 1
		}
	}
	return
}
// Replaces all different kinds of apostrophes with a single
// kind: "'" -- that is, "\x27", or unicode codepoint 39.
//