func New(desc string, rt *unicode.RangeTable) M {
	return M{rt, desc}
}
Matcher constructors
New creates a new matcher from a given match function.
package matcher
import (
	"strings"
	"unicode"
	"golang.org/x/text/unicode/rangetable"
)
type M struct {
	rt   *unicode.RangeTable
	desc string
}
func (m M) Matches(r rune) bool { return unicode.Is(m.rt, r) }
func (m M) String() string { return m.desc }