func (m *FixedLengthMatcher) Match(s string) (offset int, matchStr string) {
	if len(s) < m.length || !m.match(s) {
		offset = -1
		return
	}
	return m.length, s[:m.length]
}
func (m *FixedLengthMatcher) Match(s string) (offset int, matchStr string) {
	if len(s) < m.length || !m.match(s) {
		offset = -1
		return
	}
	return m.length, s[:m.length]
}
func ( m * FixedLengthMatcher ) Match ( s string ) ( offset int , matchStr string ) { if len ( s ) < m . length || ! m . match ( s ) { offset = - 1 return } return m . length , s [ : m . length ] }
// Match against fixed length pattern.
Match against fixed length pattern .