1// Copyright 2015 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package precis
6
7import (
8	"unicode/utf8"
9)
10
11// TODO: Add contextual character rules from Appendix A of RFC5892.
12
13// A class is a set of characters that match certain derived properties. The
14// PRECIS framework defines two classes: The Freeform class and the Identifier
15// class. The freeform class should be used for profiles where expressiveness is
16// prioritized over safety such as nicknames or passwords. The identifier class
17// should be used for profiles where safety is the first priority such as
18// addressable network labels and usernames.
19type class struct {
20	validFrom property
21}
22
23// Contains satisfies the runes.Set interface and returns whether the given rune
24// is a member of the class.
25func (c class) Contains(r rune) bool {
26	b := make([]byte, 4)
27	n := utf8.EncodeRune(b, r)
28
29	trieval, _ := dpTrie.lookup(b[:n])
30	return c.validFrom <= property(trieval)
31}
32
33var (
34	identifier = &class{validFrom: pValid}
35	freeform   = &class{validFrom: idDisOrFreePVal}
36)
37